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REFERENCES cited in text and synonymies should all be included in the list at the end of the paper, using the Harvard System (ibid., idem, loc. cit., op. cit. are not acceptable): (a) Author’s name and year of publication given in text, e.g.: “Smith (1969) describes .. .” ‘Smith (1969: 36, fig. 16) describes .. .” “As described (Smith 1969a, 19696; Jones 1971)’ ‘As described (Haughton & Broom 1927)...’ ‘As described (Haughton et al. 1927)...’ Note: no comma separating name and year Dagination indicated by colon, not p. names of joint authors connected by ampersand et al. in text for more than two joint authors, but names of all authors given in list of references. (b) Full references at the end of the paper, arranged alphabetically by names, chronologically within each name, with suffixes a, b, etc. to the year for more than one paper by the same author in that year, e.g. Smith (1969a, 19695) and not Smith (1969, 1969a). For books give title in italics, edition, volume number, place of publication, publisher. For journal article give title of article, title of journal in italics (abbreviated according to the World list o, Scientific periodicals. 4th ed. London: Butterworths, 1963), series in parentheses, volume number, part number (only if independently paged) in parentheses, pagination (first and last pages of article). Examples (note capitalization and punctuation) BULLOUGH, W. S. 1960. Practical invertebrate anatomy. 2nd ed. London: Macmillan. FIsCHER, P.—H. 1948. Données sur la résistance et de le vitalité des mollusques. J. Conch., Paris 88: 100-140. FiscHer, P.-H., DuvaL, M. & Rarry, A. 1933. Etudes sur les échanges respiratoires des littorines. Archs Zool. exp. gén. 74: 627-634. Konn, A. J. 1960a. Ecological notes on Conus (Mollusca: Gastropoda) in the Trincomalee region of Ceylon. Ann. Mag. nat. Hist. (13) 2: 309-320. Konn, A. J. 19606. Spawning behaviour, egg masses and larval development in Conus from the Indian Ocean. Bull. Bingham oceanogr. Coll. 17 (4): 1-51. THIELE, J. 1910. Mollusca: B. Polyplacophora, Gastropoda marina, Bivalvia. In: SCHULTZE, L. Zoologische und anthropologische Ergebnisse einer Forschungsreise im westlichen und zentralen Siid-Afrika 4: 269-270. Jena: Fischer. Denkschr. med.-naturw. Ges. Jena 16: 269-270. (continued inside back cover) ANNALS OF THE SOUTH AFRICAN MUSEUM ANNALE VAN DIE SUID-AFRIKAANSE MUSEUM Volume 77 7 Band June 1979 Junie Part 10 #£Deel UPPERMOST ALBIAN (STOLICZKAIA DISPAR ZONE) AMMONITES FROM THE ANGOLAN LITTORAL By M. R. COOPER & Wiad) KENNEDY Cape Town Kaapstad The ANNALS OF THE SOUTH AFRICAN MUSEUM are issued in parts at irregular intervals as material becomes available Obtainable from the South African Museum, P.O. Box 61, Cape Town Die ANNALE VAN DIE SUID-AFRIKAANSE MUSEUM word uitgegee in dele op ongereelde tye na gelang van die beskikbaarheid van stof Verkrygbaar van die Suid-Afrikaanse Museum, Posbus 61, Kaapstad OUT OF PRINT/UIT DRUK 1, 2(1-3, 5-8), 3(1-2, 4-5, 8, t.—p.i.), 5(1-3, 5, 7-9), 6(1, t.—p.i.), 711-4), 8, 9(1-2, 7), 10(1-3), 11(1-2, 5, 7, t.—p.i.), 15(4—-5), 24(2), 27, 31(1-3), 32(5), 33 Copyright enquiries to the South African Museum Kopieregnavrae aan die Suid-Afrikaanse Museum ISBN 0 908407 76 9 Printed in South Africa by In Suid-Afrika gedruk deur The Rustica Press, Pty., Ltd., Die Rustica-pers, Edms., Bpk., Court Road, Wynberg, Cape Courtweg, Wynberg, Kaap UPPERMOST ALBIAN (STOLICZKAIA DISPAR ZONE) AMMONITES FROM THE ANGOLAN LITTORAL By M. R. COoPER Queen Victoria Museum, Salisbury & W. J. KENNEDY Geological Collections, University Museum, Oxford (With 82 figures) LMS. accepted Il December 1978] ABSTRACT Rich, well-preserved collections of late Albian (Stoliczkaia dispar Zone) ammonites from the Angolan littoral provide the basis for discussion of the ontogenetic and intraspecific variation within S. (Stoliczkaia) tenuis Renz, Tetragonites jurinianus (Pictet), Eogaudryceras italicum Wiedmann & Dieni, Desmoceras latidorsatum perinflatum subsp. nov., Phylloceras (Hypophylloceras) seresitense Pervinquiere, Anisoceras haasi sp. noy., and Mortoniceras (Durnovarites) collignoni sp. noy. Other important elements present include Idiohamites dorsetensis Spath, J. pygmaeus sp. nov., I. cf. elegantulus Spath, Anisoceras armatum (J. Sowerby), A. perarmatum Pictet & Campiche, A. phillipsi sp. nov., Mortoniceras (Durno- varites) perinflatum (Spath), M. (D.) subquadratum Spath, M. (Angolaites) simplex (Choffat), M. (A.) gregoryi (Spath), Cantabrigites? curvatum Renz, Hysteroceras? cf. ootaturense (Stoliczka) and Borissiakoceras sp. nov. ? aff. reymenti (Brunnschweiler). The faunas form the basis for discussion of the subdivisions of the Stoliczkaia dispar Zone, and a return to the simple division into subzones of S. (Faraudiella) blancheti below and M. (Durnovarites) perinflatum above is proposed. CONTENTS PAGE Introduction . 3 : : 3 : , ; 6 Systematic palaeontology . 5 3 ; é so iesikata! Family Phylloceratidae : ; : ; nee lari, Genus Phylloceras . ; : ; F a wae Family Tetragonitidae . j ; ; ; a RSI Genus Tetragonites : : : : 5 Altsil Family Gaudryceratidae ; ; ; 2 a 6189 Genus Eogaudryceras . : ; , galls) Family Ancyloceratidae : : p ; 7) 196 Genus Anisoceras . : ; ; : ~ L196 Genus Idiohamites . ; ; 4 : ne 222. Family Hamitidae . : - : : ; 226 Genus Hamites . : : ; : e226 Family Turrilitidae : : : : : se DRS Genus Mariella. 3: ; F : 5 DRS Family Desmoceratidae : ; j : = 235 Genus Puzosia 2 5 : : F 35) Genus Desmoceras P F : é Se 487) 175 Ann. S. Afr. Mus. 77 (10), 1979: 175-308, 82 figs. 176 ANNALS OF THE SOUTH AFRICAN MUSEUM Systematic palaeontology (cont.) PAGE Family Lyelliceratidae . 3 5 : suc, 2Ad Genus Stoliczkaia . : : E : . 243 Family Brancoceratidae : : ‘ : 5 2X85) Genus Hysteroceras? . 4 : : . 265 Genus Mortoniceras . : : : . 269 Subgenus M. (Durnovarites) : : . 269 Subgenus M. (Angolaites) . ; j S88, Genus Cantabrigites? . ; : ; = 290 Genus Drakeoceras : : : ; Hy293 Family Binneyitidae . s ; : : 9296 Genus Borissiakoceras . : s : . 296 Age of the fauna . : : : : : : a ASS Summary : : : 5 : : ; : . 301 Acknowledgements : : : ‘ : : e303 References. ; ; ; ; : 5 : = 303 INTRODUCTION Although Albian ammonites have long been known from Angola (Szajnocha 1884; Meunier 1887; Choffat in Choffat & De Loriol 1888), Paul Choffat was the first to record uppermost Albian ammonites when he described Ammonites dispar Choffat (non d’Orbigny) (= Stoliczkaia tenuis Renz) from the environs of Catumbela. Subsequently, many authors have reported on the presence of strata with Ammonites dispar (Mouta & Borges 1926, 1928; Mouta 1937, 1954, 1956; Mouta & O’Donnell 1933) and the presence of uppermost Albian strata in Angola is now well established. In contrast, the faunal constituents of these rocks are poorly known. The collections which form the basis of this paper are from Porto Amboim, Cabo Ledo and Praia-Egito. The material from Porto Amboim comes from the lime kiln at the south side of the boat landing, and was collected mostly by C. W. Washburn on 22 July 1914, although some material from this locality, in the South African Museum, was described by Haughton (1924, 1925). Elements of this fauna were also described subsequently by Haas (1942), whose localities R28, R30 and 3041 have yielded an identical fauna in like preservation, with recrystallized test preserved. The fauna from Egito was collected by the senior author and comes from the coastal exposures at Praia-Egito where thinly-bedded limestone-shale alternations have yielded a rich fauna, mostly preserved as composite internal moulds. Faunas collected by the senior author from the Quissama Ridge, the promontory on which stands the Farol de Cabo Ledo, were obtained from road gravels and may represent more than one faunal horizon. These faunas include a number of new species, and also populations, of S. (Stoliczkaia), Mortoniceras (Durnovarites), E. (Eogaudryceras), Phylloceras (Hypophylloceras), D. (Desmoceras), Anisoceras and Tetragonites which provide unique information on the intraspecific variation, development and morphology of these ammonites. Furthermore, the composition of the faunas provides an opportunity for discussion of the stratigraphic and geographic distribution of the late Albian Stoliczkaia dispar Zone fauna. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 177 SYSTEMATIC PALAEONTOLOGY The following abbreviations are used to indicate the source of material: BM _ British Museum (Natural History), London SAM_ South African Museum, Cape Town USNMNH USS. National Museum of Natural History, Washington D.C. Measurement abbreviations are as follows: D, diameter; H, whorl height; W, whorl width (intercostal unless otherwise specified); U, diameter of umbilicus between umbilical seams; W/H, whorl width/height ratio. All measurements are given in millimetres and dimensions, as a percentage of the diameter, follow in parentheses. Class CEPHALOPODA Cuvier, 1797 Subclass AMMONOIDEA Zittel, 1884 Order PHYLLOCERATIDA Arkell, 1950 Superfamily PHYLLOCERATACEAE Zittel, 1884 Family Phylloceratidae Zittel, 1884 Subfamily Phylloceratinae Zittel, 1884 Genus Phylloceras Suess, 1865 Subgenus Hypophylloceras Salfeld, 1924 Type species Phylloceras onoense Stanton, 1895 Phylloceras (Hypophylloceras) seresitense Pervinquiére, 1907 Figs 1-2, 31 Ammonites velledae Pictet & Campiche (non Michelin), 1860: 268, pl. 36 (fig. 8). Stoliczka, 1865: 116, pl. 59 (figs 1-3). Phylloceras velledae (Michelin) Kossmat 1895: 12, pl. 1 (fig. 3). Boule, Lemoine & Thévenin, 1906: 7, pl. 1 (figs 6, 11), fig. 2. Crick, 1907: 166, pl. 10 (figs 10-11). Bose, 1923: 119, pl. 7 (figs 15-17). Spath, 19254: 180. Besairie, 1936: 164, pl. 16 (fig. 1). Venzo, 1936: 66, pl. 5 (fig. 4). Haas, 1942: 146, pl. 27 (fig. 1), pl. 44 (fig. 1), fig. 19. Matsumoto, 1942: 676. Almela & Revilla, 1957: 17, pl. 3 (fig. 2). Anderson, 1958: 180, pl. 16 (fig. 4). Phylloceras velledae var. seresitense Pervinquiére, 1907: 52; 1910: 9, pl. 1 (figs 1-3), fig. 2. Phylloceras tanit Pervinquiére, 1907: 53, pl. 3 (figs 3-9), fig. 5. Phylloceras angolaense Haughton, 1924: 85, pl. 1 (figs 1-2); 1925: 267, pl. 12 (figs 1-2). Phylloceras seresitense Pervinquiére, Spath, 1923: 18, pl. 1 (fig. 2), pl. 2 (fig. 1). Collignon (in Besairie) 1936: 190, pl. 21 (figs 1-2). Fabre, 1940: 211, pl. 5 (fig. 1). Phylloceras boulei Collignon, 1928: 144, pl. 15 (fig. 5), fig. 1. Hyporbulites seresitensis (Pervinquiére) Breistroffer, 1947: 82. ; Phylloceras (Hyporbulites) seresitense Pervinquiére, Collignon 1950: 66; 1963: 4, pl. 241 (fig. 1038), pl. 242 (fig. 1041). 178 ANNALS OF THE SOUTH AFRICAN MUSEUM Hyporbulites seresitensis var. raynaudiensis Collignon, 1956: 16, pl. 4 (fig. 1). Neophylloceras seresitense (Pervinquiére) Matsumoto, 1959: 55, pl. 12 (figs 4-5), fig. 3. ? Phylloceras (Euphylloceras) vohipalense Collignon, 1962: 1, pl. 215 (fig. 940). ? Phylloceras sp. (Ph. velledae ?) da Silva, 1962: 26, pl. 15 (figs 1-3). Hypophylloceras seresitense seresitense (Pervinquiére) Wiedmann, 1962a: 142, pl. 8 (figs 1-2) fig. 8; 19625: 249, pl. 16 (fig. 1). Hypophylloceras seresitense tanit (Pervinquiére) Wiedmann, 1962a: 142; 19625: 250, fig. 2. Phylloceras (Hypophylloceras) seresitense seresitense Pervinquiére, Wiedmann, 1964: 221, pl. 15 (fig. 4), pl. 21 (fig. 1), fig. 52. Wiedmann & Dieni, 1968: 26. Kennedy & Klinger, 1977a: 364, pl. 4 (fig. 6), pl. 6 (fig. 4), pl. 7 (fig. 4), pl. 9. Renz, 1968: 17, pl. 1 (fig. 1). Phylloceras (Hypophylloceras) seresitense tanit Pervinquiére, Wiedmann, 1964: 226, pl. 21 (figs 2-3), fig. 54. Wiedmann & Dieni, 1968: 26, pl. 1 (fig. 6), pl. 3 (figs 1-2). Phylloceras (Hypophylloceras) seresitense boulei Collignon, Wiedmann, 1964: 224, pl. 20 (figs 2-3), fig. 53. Renz, 1968: 18, pl. 1 (fig. 2), figs 6a, 7c. Forster, 1975: 140, pl. 1 (fig. 1), fig. 27. ? Phylloceras (Hypophylloceras) seresitense vohipalense Collignon, Foérster, 1975: 139, fig. 26. ? Phylloceras serum vat. perlobata Zwierzycki (non Sayn), 1913: 323, figs a-c. ? Phylloceras ex aff. ramosi Meek, Collignon, 1928: 1, pl. 1 (figs 2-4). ? Phylloceras aff. tanit Pervinquiere, Matsumoto, 1942: 674, fig. 2. Phylloceras cf. seresitense Pervinquiere, Wright & Wright, 1951: 12. ? Phylloceras cfr. semistriatum Choffat (non d’Orbigny), 1903: 17, pl. 1 (fig. 10). Material Ten specimens, SAM-6527, USNMNH 236897-236904, 237013, all with recrystallized shell preserved, and all from Porto Amboim. ~ Description The coiling is very involute, with a narrow, crater-like umbilicus (6-7°% of the diameter). The whorl section is strongly compressed, elliptical (W/H = 0,55-0,67). The flanks are slightly convex, with maximum width just below midflank, converging to a narrow, evenly rounded venter. Ornament comprises fine, flexuous lirae, very faint or completely effaced on the inner half of the flanks (faint growth striae suggest they were prorsiradiate there), recurving at about midflank so as to pass straight or slightly backwards across the venter. On USNMNH 236897 there are about 128 lirae per half-whorl. None of the present specimens shows the sutures. Measurements No. D H W W/x U USNMNH 236897 37 21(57) 13(35) 0,62 2,6(7) 9 26,5 15,5(58) +8,5(32) 0,55 USNMNH 236898 2 30,5(59) 17,5(34) 0,57 3(6) 9 35 19(54) 11(31) 0,58 ? USNMNH 236900 I) 8(53) 5(33) 0,63 1,1(7) 99 1] 5,5(50) 3,7(34) 0,67 ? USNMNH 236901 17 10(59) 6,5(38) 0,65 1,0(6) USNMNH 23690221 12(57) 717) - <0:64umeee UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 179 Fig. 1. Phylloceras (Hypophylloceras) seresitense Pervinquiére. A-B. USNMNH 236899. C-E. USNMNH 236904. F-H. USNMNH 236897. I-K. USNMNH 236903. L-N. USNMNH 236898. O-P. USNMNH 236902. Q-S. USNMNH 236901. T-V. USNMNH 236900. x1. 180 ANNALS OF THE SOUTH AFRICAN MUSEUM Intraspecific variation Wiedmann (1964: 221) recognized three subspecies within P. (H.) seresitense: P. (H.) seresitense seresitense—whorl section moderately compressed, whorl width to height ratio up to 0,65. Umbilicus very narrow. P. (#.) seresitense boulei Collignon—whorl section very compressed (W/~ = 0,50-0,57), with very narrow umbilicus. P. (H.) seresitense tanit—whorl section compressed, but with moderately open umbilicus. The most noteworthy variation in the population before the writers is in the degree of inflation of the whorls. As can be seen from Figure 2 the variation in this respect (W/H = 0,55-0,67) includes individuals of all of Wiedmann’s (1964) subspecies and, since they are all broadly contemporaneous (ranging from Aptian to Cenomanian), appear to have little biological significance. The authors find, therefore, the application of the subspecies boulei and tanit inappropriate to the present collection. Discussion The holotype of Phylloceras angolaense Haughton is in the South African Museum, SAM-6527. The specimen is entirely septate and is replaced by crystalline calcite. The shell is strongly compressed and very involute, with a very narrow, deep umbilicus. The flanks are slightly convex, almost flat, and converge towards the narrow, evenly rounded venter (Fig. 31). Maximum width is about one-quarter of the way up the flanks. Ribbing is very faint on the inner half of the flanks, although growth striae suggest it was prorsiradiate here. On the outer half of the flanks, the ribs recurve so as to become almost radial. The ribbing is very fine, with fourteen ribs in a distance of 10 mm along the venter on the adoral quarter of the outer whorl. There are no features by which P. angolaense may be satisfactorily dis- tinguished from P. seresitense and consequently the authors follow Wiedmann (1962a, 19626) in regarding it as a junior subjective synonym of Pervinquiére’s species. Phylloceras velledae (Michelin) (Wiedmann 1964: 209, pl. 11 (fig. 1), pl. 13 (fig. 4), pl. 21 (fig. 4), fig. 49) typically differs from the present species in having more convex flanks, with much coarser, more flexuous lirae, and a suture which shows diphyllic saddles in immaturity rather than tetraphyllic saddles as in P. (H.) seresitense. Hypophylloceras yeharai Nakai & Matsumoto (1968: 4, pl. 1 (figs 1-3), pl. 3 (fig. 1)) is based upon crushed material said to differ from P. (H.) velledae in its more compressed whorls (? enhanced by crushing) and less numerous and broader lirae. Kennedy & Klinger (1977a) have recently demonstrated the wide range of variation within contemporaneous populations of P. (H.) velledae and UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 181 oo o WIDTH MIGHT COP 0 30 60 90 120 DAME ER) ee ————EEeEEe——E————— Fig. 2. Plot of inflation (whorl width/height ratio) versus diameter for Phylloceras seresitense Pervinquiére, showing the unsatisfactory separation of subspecies. Circles = present Angolan material; dots = P. seresitense tanit Pervinquiere; square = holotype of P. angolaense Haughton; open triangles = P. seresitense seresitense Pervinquiere; black triangles = P. seresitense boulei Collignon. (Data after Stoliczka 1865, Spath 1923, Wiedmann 1962, Collignon 1963, Wiedmann & Dieni 1968, Renz 1968, Forster 1975, and Kennedy & Klinger 1977.) figured examples (1977a: pls 10-11) as coarsely ribbed as the Japanese material, suggesting that P. (H.) yeharai may be within the limits of variation of P. (H.) velledae. Occurrence Phylloceras (Hypophylloceras) seresitense ranges from Upper Aptian to Middle Cenomanian, and is known from southern France, Switzerland, southern England, Spain, Tunisia, Algeria, Sardinia, the Balearics, southern India, Japan, Alaska, California, Mexico, Angola, Zululand, possibly Tanzania, and Madagascar. Order LYTOCERATIDA Hyatt, 1889 Superfamily LYTOCERATACEAE Neumayr, 1875 Family Tetragonitidae Hyatt, 1900 Genus Tetragonites Kossmat, 1895 Types species Ammonites timotheanus Pictet, 1848 Discussion Wiedmann (1973) has provided the most recent discussion of the Albian to Cenomanian members of this genus, recognizing three species groups. The group of 7. rectangularis possesses persistent constrictions and a straight umbilical suture, and includes 7. rectangularis Wiedmann, T. subtimotheanus 182 ANNALS OF THE SOUTH AFRICAN MUSEUM Wiedmann, 7. kitchini (Krenkel), T. subbeticus Wiedmann, T. marrei Thomel and T. blaisoni Collignon. In the group of 7. timotheanus (Pictet), constrictions are present only at an early growth stage, whilst the umbilical suture is retracted. To this group Wiedmann (1973) assigned 7. timotheanus (Pictet), T. balmensis Breistroffer, and 7. nautiloides (Pictet). Forms lacking constrictions at all growth stages are referred to the group of T. jurinianus (Pictet). Tetragonites (Tetragonites) collignoni Breistroffer, 1940 Ammonites timotheanus Stoliczka (non Mayor), 1865: 146, pl. 73 (figs 34, 6). Tetragonites collignoni Breistroffer, 1940: 110. Murphy, 1967a: 66, pl. 5 (figs 2-5), fig. 36. Forster, 1975: 147, pl. 1 (fig. 5) (with synonymy). Tetragonites subtimotheanus Wiedmann, 1962a: 131; 1973: 592, pl. 1 (fig. 5), pl. 2 (fig. 2), pl. 3 (figs 1-5), pl. 7 (fig. 8), fig. 2 (with synonymy). Tetragonites blaisoni Collignon, 1964: 31, pl. 324 (fig. 1448). Wiedmann, 1973: 601, pl. 1 (fig. 4), pl. 6 (figs 5-7), fig. 7 (with synonymy). Material One specimen, USNMNH 236916, preserved as an internal mould, from Porto Amboim. Description Shell involute, somewhat inflated, with a depressed, trapezoidal whorl section (W/H = 1,21). Umbilicus narrow (22% of the diameter), deep, with steep, almost vertical umbilical walls. Umbilical shoulder evenly rounded, with flattish flanks converging towards a broad, slightly convex venter which rounds somewhat in maturity. There are two distinct constrictions in a distance equal to the whorl height on the last portion of the outer whorl (representing part of the body chamber), although the number of constrictions per whorl is unknown. The constrictions are markedly prorsiradiate across the inner flanks, recurving strongly in the region of the ventrolateral angulations to cross the venter with a prominent concave sinus. Measurements No. D H W W/H \UJ USNMNH 236916 44 21,5(49) +26(59) 1,21 +9,5(22) Discussion Problems concerning the specific identification of constricted tetragonitids become very clear from the recent literature concerning this group (Wiedmann 1962a, 19626, 1973; Collignon 1963, 1964; Murphy 1967a, 1967b; Wiedmann & Dieni 1968; McLearn 1972; Forster 1975; Kennedy & Klinger 19775). Forster (1975) has suggested that 7. swbtimotheanus and T. blaisoni are junior subjective synonyms of T. collignoni. Wiedmann (1973) rejected the latter name because it UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 183 was based upon a pyritic nucleus only 14 mm in diameter (although he retains T. kitchini and T. subbeticus as valid species even though the types are only 18 and 16 mm in diameter respectively), considering it a nomen dubium. Because the authors are at present unhappy with Wiedmann’s (1973) fine delimitation of T. subtimotheanus Wiedmann, T. rectangularis Wiedmann, T. blaisoni Collignon, and TJ. kitchini (Krenkel), all of which are broadly contemporaneous, they have some sympathy with Forster’s (1975) view in assigning the present material to T. collignoni. A C D E F G Fig. 3. A-D. Mortoniceras (Angolaites) simplex (Choffat). A. SAM-PCA4613. B. SAM- PCA4774. C. SAM-—PCA4590. D. SAM-PCA4609. E-F. Drakeoceras cf. dellense Young. E. SAM-PCA4662. F. SAM-PCA4800. G. Mortoniceras (Durnovarites) perinflatum (Spath), SAM-PCA4587. H. Mariella (Mariella) cf. oehlerti (Pervinquiére), SAM-—PCA4798. I. Phylloceras (Hypophylloceras) seresitense (Pervinquiére), the holotype of P. angolaense Haughton, SAM-6527. x1. 184 ANNALS OF THE SOUTH AFRICAN MUSEUM Occurrence Tetragonites collignoni ranges from the Lower Albian to the Middle Cenomanian, and is known from Madagascar, southern India, Zululand, Alaska, British Columbia, and Oregon. Tetragonites (Tetragonites) kitchini (Krenkel, 1910) Fig. 4 ? Ammonites timotheanus Whiteaves (non Mayor), 1876: 41, pl. 3 (fig. 2). Desmoceras (Puzosia; Latidorsella?) kitchini Krenkel, 1910: 226, pl. 22 (fig. 8). Tetragonites kitchini (Krenkel), Wiedmann 1962a: 171. Murphy, 1967a: 33, pl. 2 (figs 11-14), figs 15-16. Wiedmann, 1973: 599, pl. 1 (fig. 7), pl. 6 (figs 1, ?2-4), figs 5, 26. Tetragonites hulenensis Murphy, 1967a: 54, pl. 6 (figs 16-19), pl. 7 (figs 3, 6-8, 10), figs 28-30. Murphy, 19675: pl. 4 (figs 8-9). ? Tetragonites aff. kitchini (Krenkel), McLearn 1972: 26, pl. 4 (figs 4-5). Material A single specimen, SAM-PCA3125, from low in the coastal cliffs immediately north of the estuary at Praia-Egito (low dispar Zone). Description The shell is moderately involute (umbilicus 31,5°% of the diameter) and partially retains recrystallized shell. The whorl section is subtrapezoidal, almost subquadrate, as wide as high (W/H = 1,00), with slightly converging flanks and a flattish, slightly convex venter. The umbilicus is rather narrow and deep, with steep umbilical walls and subrounded umbilical shoulders. The ventrolateral shoulders are evenly rounded. Maximum width is at the umbilical shoulder. Fig. 4. Tetragonites kitchini (Krenkel). Lateral and ventral views of SAM-PCA3125, partially retaining recrystallized test. 1. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 185 There would appear to have been about seven slightly flexuous (prorsi- radiate concave in the terminology of Murphy (1967a)), strongly prorsiradiate constrictions on the outer whorl, which cross the venter with a concave-adoral sinus. The suture line was not observed. Measurements No. D H W W/H U SAM-PCA3125 54 25(46) 25(46) 1,00 L7G) Discussion Tetragonites kitchini differs from all other contemporaneous species of constricted Tetragonites in having less strongly inflated whorls with an almost quadrate whorl section. However, there appear to be intermediate forms to T. subtimotheanus Wiedmann and T. rectangularis Wiedmann, and the population structures of these species require investigation to fully validate their specific separation. Occurrence Tetragonites kitchini is known from the upper Lower Albian of Tanzania, California, Alaska, and perhaps British Columbia, and from the Middle or Upper Albian of Madagascar, and the uppermost Albian of Angola. Tetragonites (Tetragonites) jurinianus (Pictet, 1847) Figs 5-6 Ammonites jurinianus Pictet (in Pictet & Roux), 1847: 297, pl. 3 (fig. 3). D’Orbigny, 1850: 124. Ammonites timotheanus Pictet & Campiche (non Mayor), 1860: 289 (pars). Lytoceras (Tetragonites) epigonum Boule, Lemoine & Thévenin (non Kossmat), 1906: 186, pl. 3 (fig. 1). ? Lytoceras (Tetragonites) timotheanum Pervinquiére (non Mayor), 1907: 74 (pars.), pl. 3 (fig. 24 only). Lytoceras (Tetragonites) jurinianum (Pictet) Jacob, 1908: 19, pl. 1 (fig. 12). Latidorsella latidorsata Jacob (non Michelin), 1908: 35, pl. 5 (fig. 1 only). Lytoceras (Tetragonites) zacatecanus Bose, 1923: 127, pl. 9 (figs 11-17). Tetragonites jurinianus (Pictet) Spath, 1923: 26. Roman, 1938: 43. Breistroffer, 1940: 112. Wiedmann, 1962a: 176, pl. 14 (fig. 2), figs 37-38. Almela & Revilla, 1957: 20, pl. 4 (fig. 3). Murphy, 1967a: 23, pl. 2 (figs 1-4); figs 10-11. Renz, 1968: 19, pl. 1 (figs 6-7), figs 6d, Ja—b. Wiedmann & Dieni, 1968: 48, pl. 4 (fig. 4), pl. 5 (fig. 4). Wiedmann, 1973: 608, pl. 8 (figs 3-4). ? Tetragonites brazoensis Bose, 1927: 203, pl. 1 (figs 2-7). Tetragonites jurinianus var. angolana Haas, 1942: 170, pl. 44 (fig. 3), pl. 45 (fig. 1). Tetragonites timotheanus Matsumoto (non Mayor), 1959: 78, fig. 16. Tetragonites jurinianus angolanus Haas, Wiedmann, 1973: 609. Material Ten specimens, USNMNH 236915, 236917-21, 236977-79, all with recrystallized shell preserved, and all from Porto Amboim. 186 ANNALS OF THE SOUTH AFRICAN MUSEUM Description Shell inflated, involute, with a slightly depressed, trapezoidal whorl section in juveniles (W/H = 1,00-1,29), the venter becoming rounded in maturity. Umbilicus narrow (16-30% of the diameter), deep, with almost vertical walls and evenly rounded umbilical shoulders. The flanks are flattened, with maximum width close to the umbilical shoulder, and converge towards the venter. Up to 25 mm diameter, the venter is flattened, very slightly convex, whereafter it becomes rounded and the ventrolateral angulations disappear. At this stage the whorl section is broadly ovate. Constrictions are lacking at all observed growth stages. Measurements No. D H W W/a U USNMNH 236915 S75) 25,5(49) +28(53) 1,10 10(19) USNMNH 236917 38,5 20(52) +22(57) 10 +9(23) a 30 14,5(48) 16(53) 1,10 9(30) USNMNH 236918 43 19(44) 22,3(52) SIZ 9,8(23) USNMNH 236919 16 7,5(47) 8,5(53) 1,13 4(25) USNMNH 236920 18 8(44) 10(55) E25 +4(22) USNMNH 236921 21 10(48) +10(48) 1,00 5(24) USNMNH 236977 TRS 6,8(39) 8,5(49) Ws) 4,5(26) USNMNH 236978 17 7(41) 9(53) 1-29 4,7(28) T. jurinianus angolanus (holotype) 105 56(53) 51(48) 0,91 17(16) - 63 32(51) 34(54) 1,06 ? Intraspecific variation The intraspecific variation seen in Tetragonites jurinianus shows features which have an important bearing on the classification of tetragonitids in general. The wide range of inflation within juveniles far exceeds the range of variation admitted by Wiedmann (1973) within the constricted tetragonitids as a whole, and population studies may show his subdivisions of the group to be utilitarian rather than biologically significant. As can be seen from Figure 6, there is not only a distinct decrease in the umbilical ratio with growth, but there is also an ontogenetic increase in the height of the whorls, which become progressively less inflated. Wiedmann (1973) maintained 7. jurinianus angolanus as a separate sub- species by virtue of its narrower umbilicus (16% versus 23% of the diameter in T. jurinianus jurinianus), high-oval whorl section and large size. It appears, however, that these differences result from a comparison of different onto- genetic stages, and the authors include T. jurinianus angolanus in the synonymy of T. jurinianus sensu Stricto. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 187 Fig. 5. Tetragonites (Tetragonites) jurinianus (Pictet). A-B. USNMNH 236918. C-D, G. USNMNH 236921. E-F. USNMNH 236978. H-J. USNMNH 236977. K-M. USNMNH 236917. N-P. USNMNH 236919. Q-S. USNMNH 236920. x1. 188 ANNALS OF THE SOUTH AFRICAN MUSEUM Discussion As diagnosed by Wiedmann (1973: 606), Tetragonites nautiloides (Pictet) does not have constrictions beyond 10 mm diameter and thus closely approaches T. jurinianus. Indeed, the present material all exceeds this diameter and could, therefore, equally well be assigned to 7. nautiloides. However, Murphy (1967a) has noted that constrictions are present to 27 mm diameter in topotype material of T. nautiloides when there is considerable difficulty in distinguishing this 1,50 WA 0,70 0 30 60 90 DIAMETER (mm) —————> 40 ok 2) . é a ~-08, _ 1On 2 fe) = eJ o OR SRO os = Sees ae ae Ova ON Pare = =) 0 40 70 110 DIAMETER (mm) ————— Fig. 6. Plot of inflation (whorl width/height ratio) and umbilical ratio against diameter for examples of Tetragonites jurinianus (Pictet). Dots = present Angolan material; squares = the holotype of 7. jurinianus angolanus Haas; circles = material described by Wiedmann (1962, 1973), Murphy (1967a), Wiedmann & Dieni (1968). UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 189 species from some constricted tetragonitids, e.g. 7. rectangularis Wiedmann. Wiedmann’s (1973) diagnosis of T. nautiloides is difficult to support, since some of his figured specimens (pl. 8 (figs 2, 5)) clearly show weak constrictions at 22 and 27 mm diameter respectively, suggesting that this species may better be included in the 7. rectangularis group. Occurrence Tetragonites jurinianus ranges from Middle Albian to Lower Cenomanian, and is recorded from Switzerland, France, Sardinia, Mallorca, Madagascar, Angola, Mexico, and California. Family Gaudryceratidae Spath, 1927 Subfamily Gaudryceratinae Spath, 1927 Genus Eogaudryceras Spath, 1927 Type species Ammonites numidus Coquand, 1880 Discussion Eotetragonites was originally separated (Breistroffer 1947) from Eogaudry- ceras by the possession of strong constrictions throughout ontogeny, and a suture with irregularly bifid saddles. However, Wiedmann (19626: 35) has noted the occurrence of species which show combinations of these characters, conse- quently treating Eotetragonites as a subgenus of Eogaudryceras. As defined by him (19626), E. (Eogaudryceras) has initially trapezoidal whorls which become rounded in maturity and are ornamented by fine, flexuous lirae, whereas E. (Eotetragonites) has quadrate juvenile whorls and lacks liration. Eogaudryceras (Eogaudryceras) italicum Wiedmann & Dieni, 1968 Figs 7-11 Eogaudryceras (Eogaudryceras) italicum Wiedmann & Dieni, 1968: 34, pl. 1 (fig. 8), fig. 6. Material Ten specimens, USNMNH 236905-236914, all with recrystallized shell preserved, and all from Porto Amboim. Description Up to 23 mm diameter: shell evolute, compressed, with a wide, shallow umbilicus (30-41% of the diameter) and steep umbilical walls which merge imperceptibly with the strongly convex flanks. The whorl section is oval, depressed (W/y = 1,00-1,36), with a broadly rounded venter. The outer whorl conceals about 55 per cent of the preceding whorl. The earliest whorls are very finely lirate, almost smooth to the naked eye, with sporadic, rather distinct, prorsiradiate collars. 190 ANNALS OF THE SOUTH AFRICAN MUSEUM 24-45 mm diameter: the shell form is much as at the earlier growth stages, except that the flanks flatten slightly and the whorl section changes from slightly depressed to almost quadrate. At this stage the lirae are visible to the naked eye; they arise at the umbilical seam and pass forwards (prorsiradiate) on the lower third of the flanks. Thereafter they recurve slightly, only to flex forwards again before crossing the venter. At intervals one or two adjacent lirae are strengthened, presumably corresponding to the collars of the earliest whorls. The lirae become flat-topped, band-like, much broader than the interspaces, and of variable thickness at this stage. Greater than 46 mm diameter: in maturity the whorls become flat-sided and compressed (W/H = 0,66-0,80), with an elliptical whorl section and narrowly rounded venter. The umbilicus is moderately wide (26-33% of the diameter), shallow, with steep umbilical walls and evenly rounded umbilical shoulders. Maximum width is at about mid-flank. At this growth stage the irregular band- like ribs are split by fine, threadlike grooves. In the largest specimen (still septate at 82 mm diameter) there are still occasional strengthened ribs, followed by a slightly deeper intercostal groove. These may correspond to the collars of the earliest whorls. get Pagy.* y 4 ? eX * f7 ot ul €.' Di as f° 22 é ¢ Pa £ AS ar = - -— 7 + Ps Fig. 7. Eogaudryceras (Eogaudryceras) italicum Wiedmann & Dieni. Reconstruction of juvenile and adult shells. x1. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 191 C Fig. 8. Eogaudryceras (Eogaudryceras) italicum Wiedmann & Dieni. A~-B. USNMNH 236905. C-E. USNM 236908. 1. 192 ANNALS OF THE SOUTH AFRICAN MUSEUM Measurements No. D H W Wii U USNMNH 236905 81 37,5(46) 25(31) 0,66 21(26) i 56 25(45) IP.) O78 We3X(B1) USNMNH 236906 34 13(38) 15,5(45) 1,19 +10(29) USNMNH 236907 +47 +21(45) +18(38) 0,86 15,5(33) USNMNH 236908 71 33,5(47) +27(38) 0,80 19(27) USNMNH 236909 26 11(42) 11(42) 1,00 8(31) ss 1955 8(41) 8(41) 100 +5,5(28) USNMNH 236910 24 9(38) 8(38) 1,00 8,5(35) . 18 6,5(36) 7(39) 1,08 7(39) USNMNH 236911 15 556i) 6(40) 1,09 5(30) USNMNH 236912 22 8(36) 9(41) 1S 8(36) USNMNH 236913 y 535(62) +7,5(44) 1,36 7(41) USNMNH 236914 25 9(36) +11(44) 22 +8,5(34) E. (E. )italicum* +50 25(50) 19(38) 0,76 -+14(28) E. (E.)aenigmum* 58,3 28,3(48,5) 24(41,5) 0,86 14(24) E. (E.)b. bourritianum* 33 14(42) 20(60) 1,43 10(30) E. (E.)b. hispanicum* 47 20(42) 22(47) 1,10 13(28) Gaudryceras aff. madraspatanum Spath (non Stoliczka) 28 11,8(42) 11,8(42) 1,00 10(36) * Asterisks mark holotypes or neotypes. Intraspecific variation The most noteworthy feature of the present material is the great change in whorl section with growth. The earliest whorls show a wide range in inflation (W/H = 1,00-1,36) but, with continued growth, the shell becomes increasingly high-whorled and the whorl section becomes strongly compressed (Fig. 11). At the same time there is a slight, but distinct, tendency for the umbilical ratio to decrease (Fig. 11). Discussion E. (Eogaudryceras) italicum Wiedmann & Dieni is based upon a smooth, fragmentary internal mould from the Upper Albian of Sardinia. It agrees precisely with the present material in whorl section and relative proportions; lack of liration may simply be a reflection of different preservation. Gaudryceras aff. madraspatanum (Stoliczka) (Spath 1923: 22, pl. 1 (fig. 4)) is based upon a smooth phosphatic internal mould from the Cambridge Greensand of southern England. In relative proportions it falls well within the range of variation of the present Angolan material, and the writers would tentatively refer it, therefore, to E. italicum. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 193 Fig. 9. Eogaudryceras (Eogaudryceras) italicum Wiedmann & Dieni. A-C. USNMNH 236905. D-F. USNMNH 236906. G, K-L. USNMNH 236910. H-J. USNMNH 236909. M-O. USNMNH 236912. x1. 194 ANNALS OF THE SOUTH AFRICAN MUSEUM Fig. 10. Eogaudryceras (Eogaudryceras) italicum Wiedmann & Dieni. A-B. USNMNH 236907. C-E. 236911. A-D x1, E x2. The present sample is the largest single population of an E. (Eogaudryceras) species yet described, and shows a wide range of ontogenetic and intraspecific variation. In view of this wide range of variation, it seems probable that population studies will reduce in number the twelve species currently assigned to this subgenus, viz. E. (E.) numidum (Coquand), EF. (E.) intermedium (Fallot), E. (E.) vocontianum (Fallot), E. (E.) elegans Basse, E. (E.) shimizui Breistroffer, E. (E.) llosetae Breistroffer, E. (E.) turgidum Breistroffer, E. (E.) skoenbergense Collignon, E. (£.) bourritianum (Pictet), E. (E.) aenigmum (Haas) and E. (E.) muntaneri Wiedmann. Of other Upper Albian species of Eogaudryceras (Eogaudryceras), Wiedmann (1962a: 154) selected a neotype for E. (E.) bourritianum (Pictet) (in Pictet & Roux 1848: 298, pl. 4 (fig. 1)) and divided it into two chronological subspecies: FE. (Eogaudryceras) bourritianum bourritianum, from the uppermost Albian (dispar zone) of south-west France is characterized by its strongly depressed whorl section (W/H = 1,43), involute form (U = 30% of the diameter) and smooth whorls (the neotype is preserved as an internal mould and hence the lack of ornament may not be a diagnostic character). It differs from the Angolan material in its much more depressed whorl section and narrower umbilicus; E. (Eogaudryceras) bourritianum hispanicum Wiedmann (1962a: 155, pl. 12 (fig. 6), fig. 15) is a low Upper Albian form (associated with Hysteroceras and Mortoniceras) which was said to differ from the typical form in its less depressed, trapezoidal whorl section (W/H = 1,10), flattened venter, and greater involution (U = 28% of the diameter). It differs from E. (E.) italicum in being more involute, having a slightly more depressed whorl section and a flattened venter. E. (Eogaudryceras) aenigmum (Haas) (1942: 167, pl. 42 (fig. 3), pl. 44 (fig. 2), fig. 24) is from the Upper Albian of Angola. Crushed material assigned to this species, in the British Museum (Natural History), comes from Praia do Jombe UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 195 1,40 LEG 0,50 0 30 60 90 DIAMETER (mm) ————_ => UMBILICUS ( %) —————»> 0 100 DIAMETER (mm) —————————" Fig. 11. Plot of inflation and umbilical ratio against diameter for Eogaudryceras italicum Wiedmann & Dieni. Dots = present Angolan material; square = holotype (after Wiedmann & Dieni 1968). 196 ANNALS OF THE SOUTH AFRICAN MUSEUM where it is associated with a low Upper Albian fauna which includes Prohystero- ceras wordiei Spath, Beudanticeras beudanti (Brongniart) and Mortoniceras cf. inflatum (J. Sowerby). It is thus a contemporary of E. (E.) bourritianum hispanicum. The style of ornament is difficult to judge from Haas’s (1942) illustration, although the specimen is clearly lirate (it has shell preserved). Although its whorl width/height ratio is closely comparable to E. italicum (? due to crushing), it is much more involute (U = 24% of the diameter). Haas’s (1942) whorl section of the species shows inner whorls with a strongly fastigiate to keeled venter which suggest his material to be crushed. If true, this species may prove to have priority over E. (E.) bourritianum hispanicum. Occurrence E. (Eogaudryceras) italicum is currently known from the uppermost Albian of Sardinia, Angola, and possibly southern England. Suborder ANCYLOCERATINA Wiedmann, 1966 Superfamily ANCYLOCERATACEAE Meek, 1896 Family Ancyloceratidae Meek, 1876 Subfamily Anisoceratinae Hyatt, 1900 Genus Anisoceras Pictet, 1854 Type species Hamites saussureanus Pictet, 1847 Anisoceras (Anisoceras) perarmatum Pictet & Campiche, 1861 Figs 12A—H, 13C—D, 14A—C, 15C-—F, 16B Hamites armatus J. de C. Sowerby (non J. Sowerby), 1850: pl. 29 (fig. 13). Anisoceras perarmatum Pictet & Campiche, 1861: 65, pl. 48 (figs 7-8), pl. 49 (figs 1-3, 5-7). Pictet, 1861: 21. Ooster, 1863: 19. Pictet & Renevier, 1866: 103. Jukes-Browne, 1875: 288. Barrois, 1878: 271. Renevier, 1890: 340. Boule, Lemoine & Thévenin, 1907: 35. Ganz, 1912: 121. Spath, 1921: 289. Bése, 1923: 144. Diener, 1925: 73. Spath, 19255: 191. Barbu, 1932: 16. Roman, 1938: 52. Spath, 1939: 548, pl. 59 (figs 1-3), pl. 61 (figs 3-7), fig. 192. Breistroffer, 1947: 62. Reyment, 1955: 12, pl. 1 (fig. 1). Collignon, 1963: 50, pl. 259 (figs 1126-1127). Swensen, 1963: 67, pl. 4 (figs 1, 3, 7). Dieni & Massari, 1963: 798. Clark, 1965: 25, pl. 6 (figs 1, 3, 7). Wiedmann & Dieni, 1968: 65, pl. 6 (fig. 4), pl. 7 (fig. 9), figs 38-39. Renz, 1968: 74, pl. 13 (fig. Sa—c), pl. 14 (figs 1, 3, 5), figs 27a, 28g. Hamites (Anisoceras) perarmatus (Pictet & Campiche) von Hauer, 1861: 644, pl. 2 (figs 2-4). Pervinquiére, 1907: 85. Hamites (Anisoceras) saussureanus von Hauer (non Pictet), 1861: 644, pl. 2 (fig. 1). Anisoceras armatus Stoliczka (non J. Sowerby), 1866: 174, pl. 81 (figs 8-10), pl. 82 (fig. 1). Hamites perarmatus (Pictet & Campiche) Neumayr, 1875a: 30; 18755: 898. ? Anisoceras yraconense Renz, 1968: 75, pl. 16 (fig. 2), fig. 27b. Anisoceras perarmatum simplex Renz, 1968: 75, pl. 13 (fig. 7), pl. 14 (fig. 4), fig. 27k. ? Anisoceras pseudopunctatum Pictet & Campiche, 1861: 74, pl. 52 (figs 1-3). Breistroffer, 1947: 62. Renz, 1968: 79, pl. 16 (figs 1, 3, 5). Wiedmann & Dieni, 1968: 72. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 197 Fig. 12. A-H. Anisoceras perarmatum Pictet & Campiche. A-B. USNMNH 236928. C_D. USNMNH 236929, E-F. USNMNH 236944. G-H. USNMNH 236940. I-J. Anisoceras sp. juv., USNM 236745. x1. 198 ANNALS OF THE SOUTH AFRICAN MUSEUM A B C D Fig. 13. A-B. Anisoceras armatum (J. Sowerby), USNMNH 236934. C—-D. Anisoceras perarmatum Pictet & Campiche, USNMNH 236931. x1. Material Twenty-seven specimens, SAM-PCA2940, 2950, 2956, 3115, 3122, 3143, 3148, 3152, 3193, 3214, 3243, 3283, 3285, 3299, 3339, 3352, 3355, 3358, 3361 and 3391, all from Egito, SAM—PCA4801, 4804 from Cabo Ledo and USNMNH 236928-29, 236931, 236933, 236940, and 236944 from Porto Amboim, either retaining recrystallized shell or preserved as composite internal moulds. Description Whorl section varies from almost circular in specimens replaced by calcite to slightly elliptical in those crushed individuals preserved as composite internal moulds. Ornament comprises small dorsolateral to lateral tubercles and the septate bases of prominent ventrolateral spines, between which strong ribs are looped in pairs. There are sporadic non-tuberculate intercalatories between looped ribs. The main ribs are also looped across the venter, and split into fine riblets, thirteen per three dorsolateral tubercles, on the dorsum. On the body chamber there may be one to two simple ribs (SAM-—PCA3143, 3148) between looped ribs, whilst on the final shaft of USNMNH 236940, the button-and-loop ribbing is lost, and all ribs become single. Discussion Amongst contemporaneous species of Anisoceras, only A. saussureanum and A. armatum closely approach this species. Differences are noted under the discussion of A. armatum. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 199 Fig. 14. A-C. Anisoceras perarmatum Pictet & Campiche. Dorsal, lateral and ventral views of SAM-PCA3115. D-E. Anisoceras cf. armatum (J. Sowerby). A fragment of a body chamber, SAM-PCA3287, which may belong here. F. Anisoceras sp. Oblique lateral view of SAM- PCA3220. 0,75. 200 ANNALS OF THE SOUTH AFRICAN MUSEUM Anisoceras vraconense Renz (1968: 75, pl. 16 (fig. 2), fig. 27b) differs from A. perarmatum in having most ribs simple and much weaker dorsolateral tubercles. This species may be based upon a fragment of the final shaft of A. perarmatum, since the ribbing simplifies on the body chamber. Anisoceras charlottense Anderson (1958: 209, pl. 11 (fig. 3)) has a circular whorl section and very prominent looped ribs separated by three to four simple, finer intercalatories. It may be conspecific with the low Upper Albian A. salei Clark (1958: 1079, pl. 140 (fig. 3)). Anisoceras perarmatum simplex Renz (1968: 75, pl. 13 (fig. 7), pl. 14 (fig. 4), fig. 27k) is simply a variant based on a small body chamber fragment. Anisoceras pseudopunctatum Pictet & Campiche (1861: 74, pl. 52 (figs 1-3)) is based on material which, like A. perarmatum simplex, has also lost button-and- loop ribbing, and may equally be an intraspecific variant. Occurrence Anisoceras perarmatum is a typical dispar Zone species known from England, France, Switzerland, Sardinia, Tunisia, Nigeria, Madagascar, southern India, Texas, and Angola. Anisoceras (Anisoceras) armatum (J. Sowerby, 1817) Figs 13A-B, 14D-E, 16A, C, E, I, 17-19 Hamites armatus J. Sowerby, 1817: 153, pl. 168. De Haan, 1825: 152, no. 2. Buckland, 1837: 65, pl. 44 (figs 9-10). Brown, 1837: 2, pl. 2 (fig. 6). Romer, 1840: 94, pl. 15 (fig. 2). D’Orbigny, 1842: 547, pl. 135. Non Hamites armatus Mantell (non J. Sowerby), 1822: 121, pl. 23 (figs 3-4) (= A. plicatile). Baculina armata (J. Sowerby) Fleming, 1828: 250. ? Hamites undulatus Brown (non Forbes), 1837: pl. 2 (fig. 11). Non Hamites armatus J. de C. Sowerby (non J. Sowerby), 1850: pl. 29 (fig. 13) (= A. perarmatum). ? Hamites armatus J. Sowerby, Dixon, 1851: pl. 29 (fig. 13). Anisoceras armatum (J. Sowerby) Pictet & Campiche, 1861: 62, pl. 48 (figs 1-2, 4, 6). Spath, 1939: 543, pl. 59 (fig. 6), pl. 60 (fig. 1), pl. 61 ( ?figs 9-11), pl. 62 (?fig. 5), fig. 191. Swensen, 1963: 66, pl. 3 (fig. 4), pl. 4 (%fig. 6). Clark, 1965: 25, pl. 5 (fig. 4), pl. 6 (?fig. 6), fig. 7a. Renz, 1968: 75, pl. 15 (figs 1, 3), figs 27d, 28a. ? Hamites (Anisoceras) armatus J. Sowerby, von Hauer, 1861: 644, pl. 1 (figs 9-10). Non Anisoceras armatum Stoliczka (non J. Sowerby), 1866: 174, pl. 81 (figs 8-10), pl. 82 (fig. 1) (= A. perarmatum). Hamites (Anisoceras) armatus J. Sowerby, Kossmat, 1895: 149. ? Anisoceras armatum (J. Sowerby) Choffat, 1905: 41, pl. 1 (fig. 6). Non Hamites (Anisoceras ?) armatus Pervinquiére (non J. Sowerby), 1907: 84, pl. 4 (figs 2-3) (= ? A. exoticum). Anisoceras aff. armatum (J. Sowerby) Adkins, 1920: 69. ? Hamites cf. armatus J. Sowerby, Passendorfer, 1921: 237. Anisoceras cf. armatum (J. Sowerby) Bose, 1923: 143, pl. 10 (figs 22-24). Haughton, 1924: 94. Clark, 1958: 1080, pl. 139 (fig. 2). Non Anisoceras aff. armatum (J. Sowerby) Spath, 19255: 190 (= A. raynaudi). Anisoceras picteti Spath (non Matheron), 1926a: 432. Spath, 1939: 554, pl. 59 (fig. 4), pl. 61 (fig. 8), pl. 63 (figs 3, 8), fig. 194. Renz, 1968: 76, pl. 13 (figs 8-9), pl. 14 (figs 6-9), pl. 15 (fig. 4), figs 27c, 28f. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 201 Fig. 15. A-B. Anisoceras sp. Oblique dorsolateral and lateral views of SAM-PCA3301 from Egito. C-F. Anisoceras perarmatum Pictet & Campiche. C-—D. Ventral and lateral views of SAM-PCA3154. E-F. Lateral and ventral views of SAM-PCA4801. G-—H. Anisoceras sp. An indeterminate body chamber fragment from Egito, SAM—PCA2942. I-J. Mortoniceras (Angolaites) simplex (Choffat). Lateral and ventral views of SAM-PCA3249. A-D, G-H 0,75, E-F, I-J x1. 202 UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL ? Hamites aff. armatus J. Sowerby, Scott, 1926: 80. Bése, 1928: 146. Adkins, 1928: 24. ? Anisoceras cf. armatum (J. Sowerby) Passendorfer, 1930: 667. ? Non Hamites (Anisoceras) armatus Collignon (non J. Sowerby), 1932: 20, pl. 4 (fig. 1). Anisoceras saussureanum var. spinosa Haas, 1942: 192, pl. 46 (figs 1-3), fig. 30. Non Anisoceras armatum Haas (non J. Sowerby), 1942: 189, fig. 29 (= A. tropicale). Anisoceras jacobi Breistroffer, 1946: 310; 1947: 62. Wiedmann & Dieni, 1968: 67, pl. 6 (fig. 13), fig. 41. ? Anisoceras aff. picteti Spath, Kennedy, 1971: 13, pl. 3 (fig. 6), pl. 7 (fig. 10). ? Non Anisoceras armatum (J. Sowerby) Kennedy, 1971: 14, pl. 5 (fig. 11). Material Fourteen specimens, SAM—PCA2932, 2947, 2953, 3174, 3364, and 3398 from Egito, USNMNH 236930, 236934, 236936-37, 236939, and ?236952 from Porto Amboim, and SAM-—PCA4606 and 4610 from Cabo Ledo. Description Shell form suggests initial coiling in an open planispiral, straightening in maturity. The whorl section is approximately circular. The ornament is rather variable, comprising slightly rursiradiate to slightly prorsiradiate looped ribs, tetween which are generally one, sometimes two, simple intercalatories. Looped ribs are ornamented with small pointed dorso- lateral tutercles and the septate bases of prominent ventrolateral spines. All rits are of more or less equal strength. Across the dorsum the ribs divide into fine riblets and are accompanied by intercalatories. In USNMNH 236939, which is taken to represent an early portion of the spire of the species, main ribs are weakly looped and are separated by two to three intercalatories. In USNMNH 236952, the largest specimen (which is, however, still septate), the whorl section is slightly compressed, oval, and there is generally only one intercalatory between looped ribs, although even these are sometimes absent. Discussion Anisoceras armatum is a widely-cited but poorly understood species, and in consequence the holotype is refigured here (Fig. 17). As noted by Spath (1939: 546), this is a crushed, composite internal mould which shows the following features: the penultimate shaft has distinct looped ribs separated by only one non-tuberculate intercalatory which is of approximately the same strength as the looped ribs. At this stage there are about five ribs in a distance equal to the whorl height (allowing for post mortem crushing). On the hook, the preservation is poor, but the looped ribs clearly break up so as all to become single on the final non-septate shaft. At this stage there are still only about five ribs in a distance equal to the whorl height, and most of the ribs are of approximately the same strength. The dorsolateral tubercles are still present in maturity, although weak and irregularly developed. It is clear from the above description, and comparison with Sowerby’s original illustration (cf. Spath 1939, fig. 191), that this species has been mis- UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 203 Fig. 16. A, C, E, I. Anisoceras armatum (J. Sowerby). A. SAM-PCA5470. C. SAM-PCAS5471. E. SAM-PCA5473. I. SAM-PCA5472. B. Anisoceras perarmatum Pictet & Campiche. Lateral view of SAM-PCA3339, showing change of ornament on the body chamber. D. Hamites duplicatus Pictet & Campiche. Lateral view of SAM-PCA2955. F. Hamites virgulatus Brongniart. Lateral view of SAM-PCA3158, showing venetzianus-type ribbing. G. Mariella (Mariella) gresslyi (Pictet & Campiche). SAM-PCA3133. H. Hamites virgulatus Brongniart. Lateral view of SAM—PCA2959, showing rather dense subvirgulatus-type ribbing. J-K. Anisoceras phillipsi sp. nov. Lateral and dorsal views of SAM-PCA 4799. B x0,75, other <1. 204 ANNALS OF THE SOUTH AFRICAN MUSEUM interpreted. Indeed, Sowerby’s figure bears no great resemblance to the original and shows too many intercalated ribs both on the penultimate and final shafts, while the differentiation of the ribs on the final shaft is less prominent than is shown in Sowerby’s drawing. Anisoceras jacobi Breistroffer (nom. nov. pro Anisoceras picteti Spath (non Matheron) 1939: 554, pl. 59 (fig. 4), pl. 61 (fig. 8), pl. 63 (figs 3, 8), fig. 194) was diagnosed as follows: “Like A. armatum, but more coarsely ornamented, with Fig. 17. Anisoceras armatum (J. Sowerby). Sowerby’s (1817, pl. 178) original figured specimen from the Upper Greensand of Roak, near Benson, Oxfordshire. Oxford University Museum K67S5a. x 1. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 205 A B C Fig. 18. A-C. Anisoceras armatum (J. Sowerby), USNMNH 236952. x1. the intermediate ribs (one, rarely two) as prominent as the main ribs that meet at the strong tupercles. Suture-line similar to that of A. armatum.’ These are the exact features which characterize the penultimate shaft of the holotype of the contemporaneous A. armatum, and the authors regard A. jacobi as a junior subjective synonym of A. armatum. Anisoceras armatum and A. perarmatum are contemporaneous species which differ in that the latter generally lacks intercalatories between the 206 ANNALS OF THE SOUTH AFRICAN MUSEUM looped ribs in maturity, although there are intermediates between the two species, e.g. USNMNH 236952 (Fig. 18). Spath (1939) noted the very close resemblance between A. saussureanum (Pictet) and A. armatum and considered immature growth stages indistinguish- able. In maturity, A. saussureanum was said to differ by its distant tuberculation, with commonly two to three intercalatories between looped ribs, whilst coming from a lower level in the Albian. Spath (1939) appeared to place much weight, in his separation of the above two species, on the supposedly lower horizon of /. ih” . € : i N aor wy ne Se pet | at acme = A B ; 22th i dj 4; E F G H Fig. 19. Anisoceras armatum (J. Sowerby). A-B. USNMNH 236930. C-D. USNMNH 236936. E-F. USNMNH 236937. G—H. Doubtful juvenile, USNMNH 236939. x1. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 207 A. saussureanum, although Breistroffer (1940, 1947) and Renz (1968) record it from the uppermost Albian of France and Switzerland respectively. Moreover, A. saussureanum spinosum (Haas) is recorded from the uppermost Albian of Angola and Mexico (fide Haas 1942). The holotype of A. saussureanum spinosum comes from the same locality as the Washburn collection and the authors have no hesitation in regarding it as a junior subjective synonym of A. armatum. However, Haas’s identification clearly focuses on the difficulties of separating A. armatum and A. saussureanum and, in view of the fact that they are contem- porary species in the uppermost Albian, they probably do not bear specific separation. However, until the type and topotype material of A. saussureanum are restudied with regard to their intraspecific variation, it seems preferable to retain these two well-known species separate. Anisoceras tropicale (Meunier) (1887: 62, pl. | (fig. 5)) is based upon a very poorly preserved internal mould which was tentatively referred to A. armatum by Choffat (1905: 41) and Haas (1942: 191), although Spath (1939: 558) considered it closer to A. pseudoelegans. Meunier’s specimen shows three fine intercalatories between looped ribs and, judging from the locality, a valley to the north of Lobito, is somewhat older than A. armatum. This is supported by the example of A. armatum figured by Haas (1942, fig. 29), which the authors would assign to A. tropicale; it occurs on the reverse side of the holotype of Mortoniceras vokesi (Haas), topotype material of which comes from the mid-Upper Albian zone of Elobiceras elobiense (Cooper 1978) at Lobito, in association with Puzosia cuvervillei (Meunier). Anisoceras exoticum Spath (1939: 555, pl. 59 (fig. 7), pl. 60 (fig. 4), pl. 63 (fig. 2), fig. 195) differs from A. armatum in having four to six intercalatories between main ribs, with very feebly-developed dorsolateral tubercles. The ribbing of this species is also attenuated across the siphonal line. In Anisoceras oldhamianum (Stoliczka) (1865: 135, pl. 83 (figs 1-4), pl. 92 (fig. 1)) all the ribs of the early growth stages are tuberculate and presumably looped, whilst on the straight shaft there is a fine, non-tuberculate rib separating looped ribs. The early whorls are coiled in a shallow, open helix. Occurrence Anisoceras armatum is at present known with certainty only from the uppermost Albian of southern England, France, Switzerland, Sardinia, Angola, Texas, and Mexico. Anisoceras haasi sp. nov. Figs 20-22 Idiohamites (?) indet. sp., Haas, 1942: 195, pl. 45 (fig. 6). Idiohamites spiniger Haas (non J. Sowerby), 1942: 195, pl. 46 (fig. 4), fig. 31a—b. Idiohamites indet. sp., Haas, 1942: 197, pl. 45 (fig. 7), fig. 31c. Idiohamites aff. subspinigero Haas (non Spath), 1942: 197, pl. 46 (fig. 5), fig. 31d-e. 208 Pe ie it i * . * “ pes oe ee paceilh Skat oe 5 ee aes SS si sone a teititen “iy, ANNALS OF THE SOUTH AFRICAN MUSEUM aes Be, SE pei ior MUTE IE AE i, 4 “ a Fig. 20. Anisoceras haasi sp. nov. Reconstruction of early and middle growth stages. x1. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 209 Fig. 21. Anisoceras haasi sp. nov. A-C. USNMNH 236923. D, F, H. USNMNH 236924. E, G. USNMNH 236922. I-J. USNMNH 236925. x1. 210 ANNALS OF THE SOUTH AFRICAN MUSEUM Material Seven specimens, USNMNH 236922-7, all retaining recrystallized shell and all from Porto Amboim, together with a single crushed internal mould, SAM-PCA2952 from Praia-Egito. Type material USNMNH 236922 is designated holotype; the remaining specimens from Porto Amboim are paratypes. Etymology Named for Otto Haas, pioneer of ammonite studies on the Angola Cretaceous. Diagnosis A densely ribbed species of Anisoceras with 8-15 ribs in a distance equal to the whorl height; 2 or 3 ribs are looped from small, acute dorsolateral tubercles to prominent rounded bases of septate ventrolateral spines, commonly with 3-4 looped between tubercles across the venter; there are between 2 and 9 fine intercalatories separating looped ribs. Whorl section circular to elliptical, compressed. Description Up to 13 mm whorl-width: at this stage, the shell is coiled in a loose planispire, and has a slightly depressed to circular cross-section. Ornament comprises fine, slightly rursiradiate ribs, about as wide as the interspaces and effaced across the dorsum. There are periodic broad bulges which follow the course of the ribbing and are ornamented with very weak, pointed dorsolateral tubercles and the septate bases of large, prominent, ventrolateral spines. The fine ribs commonly arise in pairs from the dorsolateral tubercles and are joined by a third rib to meet the ventrolateral spine-base. Three to four ribs are looped across the venter connecting the ventrolateral spines. There are four to nine fine inter- calated ribs between adjacent bulges. 14-16 mm whorl-width: beyond 13 mm whorl width, the shell begins to uncoil, developing an almost straight shaft. At the same time, the whorl section becomes slightly compressed (“/yH = 0,83-0,86) and elliptical. The bulges become more regular with generally three in a distance equal to the whorl height, and commonly with two to three fine ribs separating adjacent bulges. Ribbing remains rursiradiate at this stage and the dorsolateral tubercles have migrated up flank to a low lateral position. Discussion The lectotype of A. pseudoelegans (Renz 1968, pl. 14 (fig. 12)) differs from the Angolan material in having a strongly compressed whorl section with flattened flanks and maximum width near the dorsolateral tubercles, whilst it is UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 21 & . Fig. 22. Anisoceras haasi sp. nov. Dorsal and lateral views of a slightly crushed composite internal mould, SAM—PCA2952, from Egito. x1. more coarsely ribbed, with ribs arising in bundles from distinctly bullate dorso- lateral tubercles. Juveniles of A. pseudoelegans also appear to be much more coarsely ribbed than the present material (compare Renz 1968, pl. 14 (figs 10-11)). According to Kennedy (1971: 12, pl. 3 (figs 12-13), pl. 4 (figs 1-3)), Anisoceras plicatile is a Middle Cenomanian species with 12 fine ribs in a distance equal to the whorl height, and a circular whorl section. 2 or 3 ribs are looped between the midlateral and ventrolateral tubercles and are separated by 1-3 non-tuberculate intercalatories. Anisoceras plicatile differs from the present material, therefore, in having much more swollen main ribs and a much more prominent lateral tubercle which is at the middle of the flank, not dorso- lateral as in A. haasi. The Angolan species also has more numerous, fine intercalatories, whilst the ribbing is not as coarse in maturity as it is in A. plicatile (compare Kennedy 1971, pl. 2 (fig. 12)). Anisoceras bendirei (Adkins) (1920: 8, pl. 11 (fig. 1)) from the late Albian of Texas differs from the Angolan material in being much more coarsely ribbed, with the lateral tubercle higher on the flanks. Anisoceras raynaudi (Boule, Lemoine & Thévenin 1907: 170, pl. 4 (figs 7-8), fig. 38) is a finely ribbed species in maturity, which differs from A. haasi in having fewer intercalatories (only 2-3) between looped ribs in the early growth stages, a more prominent dorsolateral tubercle and, judging from material from Catuane, southern Mozambique, in the South African Museum, Cape Town, in DID ANNALS OF THE SOUTH AFRICAN MUSEUM having the early whorls coiled in an open helical spire up to 20 cm in height. It is also an earlier species (orbignyi-varicosum Subzones). Anisoceras nanaense (von Hauer) (1861, pl. 1 (figs 11-12)) differs from the present species in lacking dorsolateral tubercles, and in having prorsiradiate ribs with only two to three intercalatories between tuberculate ribs. Anisoceras arrogans (Giebel) (1852: 305) (nom. nov. pro Hamites elegans d’Orbigny (non Parkinson) 1842: 542, pl. 133 (figs 1-5)) can be distinguished from A. haasi in its lack of dorsolateral tubercles, with only two to four non- tuberculate intercalatories, and in the coarse, distant ribbing of the body chamber. Occurrence Anisoceras haasi sp. nov. is at present known only from the uppermost Albian of Angola. Anisoceras phillipsi sp. nov. Figs 16J-K, 23-24 Material Eight fragments, SAM—PCA2974, 3179, 3183, 3211-3212, 3220 and 3222, all preserved as composite internal moulds, from Praia-Egito, and SAM-— PCA4799 from the Quissama Ridge at Cabo Ledo. Type material The specimen illustrated as Figure 23, SAM—PCA3183 from Praia-Egito is designated as holotype. All other specimens cited above are paratypes. Etymology The species is named for Denis Phillips of the British Museum (Natural History) who, during many years, has given both authors invaluable assistance and advice in connection with their researches. Diagnosis A large species of Anisoceras with subrectangular, depressed to ovate whorl section in maturity. Prominent dorsolateral clavae give rise to two, occasionally only one, rursiradiate ribs which meet the well-developed ventrolateral clavae singly or in pairs. There are no intercalated ribs. Across the venter the ribs are looped or single. Description In the smallest example, SAM-—PCA3179, the whorl section is elliptical, compressed, although it may have suffered lateral compaction. All the other larger fragments show a strongly depressed, subrectangular whorl section (Fig. 24) prior to the final hook, and an ovate whorl section afterwards. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 213 Fig. 23. Anisoceras phillipsi sp. nov. Dorsal, ventral and lateral views of the holotype, SAM-PCA3183, preserved as an internal mould. 0,75. 214 ANNALS OF THE SOUTH AFRICAN MUSEUM ere Fig. 24. Anisoceras phillipsi sp. nov. Whorl sections. A-B. SAM-PCA2974. C. SAM- PCA3183. D. SAM-PCA3222. x1. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL PANS) On the dorsolateral shoulder, prominent clavae give rise to commonly two, sometimes only one, coarse, rursiradiate flank ribs which, on curved fragments, are strongly convex adorally. The flank ribs meet the well-developed ventro- lateral clavi either singly or in pairs, with six to eight ribs in a distance equal to the whorl height. Across the venter, ribs are single or looped. Discussion The only species with which the present form may usefully be compared is Anisoceras arrogans (Giebel) (= Anisoceras campichei Spath 1942: 559, pl. 63 (figs 6-7), fig. 197) which differs in lacking the dorsolateral clavae and in the regular nature of its ribbing across the venter. Occurrence Anisoceras phillipsi sp. nov. is known only from the uppermost Albian of Angola. Anisoceras cf. arrogans (Giebel, 1852) Figs 25-26 Compare Hamites elegans d’Orbigny (non Parkinson), 1842: 542, pl. 133 (figs 1-5). Hamites arrogans Giebel, 1852: 305. Anisoceras pseudoelegans Pictet & Campiche, 1861: pl. 50 (figs 6-7 only). Anisoceras campichei Spath, 1926: 432; 1939: 559, fig. 197 only. Metahamites (?) arrogans (Giebel) Spath, 1939: 559. Anisoceras aff. campichei Spath, 1939: pl. 63 (figs 6-7). Anisoceras arrogans (Giebel) Wiedmann & Dieni, 1968: 69, pl. 7 (fig. 10), pl. 8 (figs 5, 7, 11), figs 46-50. Description This species is known only from large fragments. In SAM—PCA3205, the whorl section is slightly compressed, subquadrate, but the remaining material shows some variation in this character. Ornament comprises prominent, single flank ribs arising from weak umbilical tubercles and passing slightly prorsiradiate across the flanks to the bases of large, septate ventrolateral spines. Ribs are either single or looped across the venter, and the rib pattern is shown in Figure 26. There are six to seven flank ribs in a distance equal to the whorl height. Across the dorsum, fine ribs are looped between the weak dorsolateral tubercles, with generally an intercalated rib between pairs, so that there are about fifteen ribs across the dorsum per five dorsolateral tubercles. Discussion The present specimen is closest to Anisoceras arrogans (Giebel) (= A. campichei Spath, 1939: 559, fig. 197 only) from which it differs in its subquadrate whorl section, slightly prorsiradiate flank ribs, and the fact that all 216 ANNALS OF THE SOUTH AFRICAN MUSEUM ribs across the venter arise from ventrolateral tubercles. Anisoceras arrogans also does not show the peculiar zigzagging of the ribs across the venter (see Fig. 26) seen in the Angolan material. However, since A. arrogans and the. present material represent different ontogenetic stages, the differences may not be as great as they first appear, and consequently the present material is identified as A. cf. arrogans (Giebel). Fig. 25. Anisoceras cf. arrogans (Giebel). Dorsal, ventral and lateral views of SAM—PCA3205. x O75: UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL Die | Fig. 26. Anisoceras cf. arrogans (Giebel). Schematic rib pattern across the venter of SAM-PCA3205. x 0,75. Anisoceras phillipsi sp. nov. differs from the present material in the posses- sion of distinctly clavate dorsolateral tubercles, from which ribs frequently arise in pairs. Occurrence Anisoceras arrogans is known from the uppermost Albian of Switzerland, France and Sardinia, and may also be present in southern England and Angola. Anisoceras aff. exoticum Spath, 1939 Fig. 27 Compare Anisoceras saussureanum Pictet & Campiche (non Pictet), 1861: 118, pl. 1 (fig. 2). Anisoceras exoticum Spath, 1939: 555, pl. 59 (fig. 7), pl. 60 (fig. 4), pl. 63 (fig. 2), fig. 195. Material A single specimen, SAM-PCA3174, preserved as a composite internal mould, from Praia-Egito. 218 ANNALS OF THE SOUTH AFRICAN MUSEUM Description The specimen represents a slightly crushed fragment of a straight shaft in which the whorl section was originally probably almost circular. Ornament comprises slightly rursiradiate main ribs between which are three to seven fine, secondary ribs, the density of which increases adorally. The fragment lacks obvious tuberculation. Fig. 27. Anisoceras aff. exoticum Spath. A body chamber fragment, SAM-PCA3174. 0,75. Discussion The specimen is a body chamber fragment and, since ornament frequently changes drastically on the body chamber of Anisoceras, reference to Spath’s species is somewhat tentative. Occurrence Anisoceras exoticum is known from England, Switzerland, Sardinia, and possibly Angola. UPPERMOST ALBIAN AMMONITES FROM THE ANGOLAN LITTORAL 219 Anisoceras aff. subarcuatum Spath, 1939 Fig. 28 Compare Anisoceras subarcuatum Spath, 1939: 560, pl. 65 (fig. 1), pl. 66 (fig. 1), fig. 198. Material A single specimen, SAM-—PCA3143, from the dispar Zone at Praia-Egito. Description A short fragment shows affinities with Spath’s species and may belong here. The whorl section is slightly compressed, oval. Ornament comprises slightly rursiradiate, strengthened, simple main ribs which bifurcate or trifurcate across the dorsum and are ornamented with dorsolateral and ventrolateral tubercles. Between main ribs are two to three, slightly weaker, somewhat irregular secondary ribs, which occasionally bifurcate across the venter. All the secondary ribs lack tubercles. Discussion Body chamber fragments of Anisoceras are notoriously difficult to identify and hence full determination of the present specimen must await further material. Fig. 28. Anisoceras aff. subarcuatum Spath. Ventral, lateral and dorsal views of SAM-PCA3143. 0:75: 220 ANNALS OF THE SOUTH AFRICAN MUSEUM Occurrence Anisoceras subarcuatum is known with certainty only from the low Upper Albian (varicosum and auritus subzones) of southern England, but may also be present in the uppermost Albian of Angola. Anisoceras aff. spathi (Wiedmann, 1962) Fig. 29 Compare Anisoceras subarcuatum Spath, 1939: 560, pl. 63 (fig. 5 only). Idiohamites spathi Wiedmann, 1962a: 188. Material A single fragment, SAM—PCA3223, from the upper part of the dispar Zone at Praia-Egito, preserved as a composite internal mould. Fig. 29. Anisoceras aff. spathi (Wiedmann). Ventral and lateral views of SAM—PCA3223.