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CHAPTER XVI.
THE RESTORATION OF ICHTHYORNIS.
(Plates XXVI and XXXIV.)
Tue preceding description of the remains of Jchthyornis, in connection
with the illustrations given in Plates XXI to XXXIV, will make known
most of the more important characters which separate these remarkable
Mesozoic birds from all others, recent or extinct. The material on which
the present restoration of two species of this genus are made consists of
portions of more than seventy different individuals. None of these various
skeletons were as complete, when found, as were several of Hesperornis,
from the same formation. This was no doubt mainly due to the smaller
size, and more fragile character, of the individual bones of Ichthyornis
The restoration of Apatornis, evidently a near ally of Ichthyornis, has not
been attempted, as the specimens at present available for this purpose are
not sufficiently numerous or complete.
In the restoration of Ichthyornis dispar, as given on Plate XXVI, only
the remains of the type specimen are figured, as it was deemed
important to show the exact material on which the genus was based.
These portions are shaded in the restoration, and are of the natural size.
The bones represented in outline are taken in part from other specimens of
the same species, but mostly from the skeleton of the Royal Tern (Sterna
regia, Gambel), which, after a careful comparison, seemed well adapted for
completing, approximately, the restoration here presented. The position
chosen is one which seemed on the whole to accord best with the remains
at present known.
23 177
178 ODONTORNITHES.
The restoration of Ichthyornis victor, on Plate XXXIV, is also of
natural size, and is based on more complete material, including portions
of several skeletons. The other species of the genus Ichthyornis did not
differ widely from these in size, and this is true also of the known specimens
of Apatornis.
In considering the skeleton of Ichthyornis, the anatomist is at once
confronted with a strange combination of characters. The wing-bones are
conclusive proof that Ichthyornis was a highly specialized bird, with great
powers of flight. The individual bones correspond closely with those of
birds living to-day. The legs and feet, also, are much like those of some
modern birds. With these portions alone before him, the comparative
anatomist would unhesitatingly refer the remains to the class of Birds, and
would naturally conclude that they belonged to the modem type. I,
however, the skull should then be found with the wings and feet, very
strong evidence would be required to convince him that they were parts of \\
one and the same bird. The jaws and teeth present reptilian characters
wholly unknown in modern birds, while the base of the skull and the small
brain point strongly in the same direction. The biconcave vertebre lead
Ichthyornis still farther away from all known birds, recent and extinct, and,
if found alone with the jaws and teeth, would force any anatomist to the
conclusion that he had before him the remains of a reptile.
The skeleton of Ichthyornis, as we know it to-day, can be interpreted
only, in the light of modern science, by supposing that certain parts have
become highly specialized in the direction of recent birds, while others
have been derived, with but little change, from a reptilian, or even a more
lowly, ancestry. In the wings, the most characteristic modern feature is the
codssification of the metacarpal bones, a character universal among existing
birds. In reptiles, however, and in the only known Jurassic bird,
Archeopteryx, these bones are separate. The sternum of Ichthyornis is
very similar to that of modern carinate birds. In the feet of Zchthyornis,
also, the compound tarso-metatarsal is another modern feature, especially
characteristic of recent birds.
RESTORATION OF ICHTHYORNIS. 179
If, now, we consider the skull of Ichthyornis, we find the avian and
the reptilian characters strangely blended. The teeth are evidently a
strong reptilian feature, and, before the discovery of Ichthyornis, were
entirely unknown in the class of Birds. Their method of implantation in
distinct sockets is a specialized character in reptiles, and was not shared
even by Hesperornis, the contemporary of Jchthyornis. The diminutive
elongated brain, also, points back to the reptiles. Other features of
the skull, for example, the single headed quadrate, are shared only by the
most reptilian of birds. The union of the lower jaws in front, by ligament
only, is characteristic of many reptiles, and is seen in Hesperornis, but is
unknown in all other birds.'' The form of the skull and the obliteration of
most of the cranial sutures are points of resemblance to many modern birds.
The locomotive organs of Ichthyornis are so similar to those of typical
birds that they present no such interesting mechanical problems as were
suggested by the skeleton of Hesperornis. In the vertebra, however, we
find a primitive form retained, and also have the key to the origin of
one remarkable character in recent birds, which has hitherto remained
unexplained.
While all existing birds, and all of the extinct forms so far as
known, including Hesperornis, have the peculiar saddle-shaped vertebre,
those of Ichthyornis, and its near ally Apatornis, are biconcave. This form
is seen in a few recent and in many extinct Reptiles, and in the
Amphibians; but it is especially characteristic of Fishes, from which class
it was undoubtedly inherited by the superior groups. This character
alone indicates unmistakably a great antiquity for the class of birds.
The saddle-shaped vertebree are certainly one of the most marked
features in the skeleton of modern birds. This form is so peculiar and
so constant that it has been considered by many anatomists as the best
distinctive character for the class. In no other group of animals known do
we find the true saddle-shaped articulation of the centra seen in the
vertebrie of birds.?
‘In the Pelicans and Curlews, the rami unite late by ankylosis.
* An approach to this form is shown in the cervical vertebrae of the Kangaroos.
180 ODONTORNITHES.
Not only do the presacral vertebrae of all existing birds exhibit this
structure, but the many extinct species now known from the whole series of
Tertiary deposits have the same articulation. If we knew only these fossil
forms, in addition to the existing species of birds, the origin of this peculiar
vertebral articulation would perhaps remain a mystery. Most fortunately,
however, one of the vertebrae of Ichthyornis throws much light on this
point, and virtually explains the difficulty.
We have seen that Hesperornis has the same kind of vertebre as
modern birds, while those of Jchthyornis are biconcave. The marked
contrast between the shape of the vertebral articulation in these two
genera is seen in the figures below, which show a characteristic cervical
vertebra in each form. In the vertebra of Ichthyornis shown in figures 32
and 33, it will be seen that the articulation of the centrum is cup-shaped ;
while, in the corresponding vertebra of Hesperornis, the ends of the centrum
are saddle-shaped, as in ordinary birds. Thus the distinction between the
two types in this part of the skeleton is as wide as between Ichthyornis and
any living bird.
Fig. 32.
Ficure 32.—Twelfth cervical yertebra of Jchthyornis dispar, Marsh; front view; twice natural size.
Figure 33.—The same vertebra; seen from the left side.
Figure 34.—Third cervical vertebra of Ichthyornis victor, Marsh; front view; twice natural size.
Fig. 36.
Figure 35.—Thirteenth cervical vertebra of Hesperornis regalis, Marsh; front view; natural size.
Figure 36.—The same yertebra; posterior view. a. anterior articulation; d. diapophysis; p. parapophysis*
J: lateral foramen; ne. neural canal; s, neural spine; 2. pre-zygapophysis; 2’. post-zygapophysis.
RESTORATION OF ICHTHYORNIS. 181
To the evolutionist, who believes that birds are all closely connected
genetically, this difference in structure, at first sight, offers a most serious
difficulty ; since hitherto we have had no hint of a transformation from the
one form to the other.
In the third cervical vertebra of Ichthyornis, however, we catch nature
in the act, as it were, of forming a new type; by modifying one form of
vertebra into another. Following this clew, the connection between these
widely divergent types of structure soon becomes apparent; and the
development of the modern style of avian vertebra from the fish-like,
biconcave form finds a ready solution. In the anterior articulation of
this vertebra of Ichthyornis (figure 34), the surface looks downward and
forward, being inclined at an angle of nearly 60° with the axis of the
centrum. In vertical section, it is moderately convex, while transversely
it is strongly concave; thus presenting a near approach to the saddle-like
articulation. None of the other known vertebree of Ichthyornis possess this
character
_ This highly specialized feature occurs at the first bend of the neck,
and greatly facilitates motion in a vertical plane. If, now, we consider for
a moment that the dominant motion in the neck of a modern bird is in a
vertical plane, we see at once that anything that tends to facilitate this
motion would be an advantage, and that the motion itself would tend
directly to produce this modification. With biconcave vertebra, the
flexure in any direction is dependent on the elasticity of the fibrous tissue
that connects them, as the edges of the cups do not slide over each other.
An increasing movement in the neck of Ichthyornis in a vertical plane
would tend to deflect the upper and lower margins of the circular cup,
and to produce a vertical constriction, and at the same time to leave the
lateral margins projecting; and this is precisely what we have in the third
vertebra of this genus.
This modification of the vertebree would naturally appear first where
the neck had most motion, viz: in the anterior cervicals, and gradually
would be extended down the neck; and, on to the sacrum, if the same
flexure were continued.
182 ODONTORNITHES.
Behind the axis, or where the vertical motion prevails, we find in
modern birds no exception to the saddle articulation of the vertebra in the
whole cervical series,
In the dorsal vertebrae, this cause would be less efficient, since the
ribs and neural spines tend to restrict vertical motion, and hence to arrest
this modification. This region, then, as might be expected, offers strong
confirmatory evidence of the correctness of the above explanation; for
here occur, among existing birds, the only true exceptions known in the
presacral series to the characteristic saddle-shaped articulation. In Strigops
and a few other land birds; in the Penguins, the Terns, and some other
aquatic birds, one or more vertebree in the dorsal region are without the
saddle-shaped articulation, and are either opisthocclian, or imperfectly
biconcave. In such instances, we can usually, if not always, detect
evidence of an arrest of vertical flexure. This may lock together the
posterior dorsals by their neural spines, as in Strigops, leaving the power
of lateral flexure; or several vertebree may be codssified, as in Accipiter,
and some other Raptores, in which a stiff back is a positive advantage.
In the codssified sacral series of many birds, one or more of the
anterior vertebrae have the saddle-shaped articulation. This, however, is
no valid objection to the above explanation, since these vertebre are really
dorsals, and have gradually coalesced with the true sacral vertebre.
In the caudal vertebrae of recent birds we have, in a measure, the
original biconcave structure preserved, for here the motion in every direc-
tion was much restricted. The caudal vertebre of these birds, even in the
most aberrant forms, are essentially the same, and in the fossil species the
articulations at least appear to follow the general rule. In Pavo and
Geoccocyx, the caudal vertebrae exhibit a tendency to a proccelian union.
Some other forms also show unimportant modifications of the normal type
of caudal articulation, but nothing to suggest a real objection to the
explanation now proposed of the origin of the saddle-shaped vertebra,
characteristic of Birds.
In bringing together the above facts, and others suggested by them,
the classification and development of the various forms of vertebree appear
to be somewhat as follows:
RESTORATION OF ICHTITYORNIS. 1835
(1.) Biconcave vertebre (Fishes and Amphibians); the primitive type ;
a weak articulation, admitting free, but limited motion. From this form,
have been directly derived the other varieties, namely :
(2.) Plane vertebre (Mammals); affording a stronger joint, with motion
still restricted.
(3.) Cup-and-ball vertebre (Reptiles); a strong and flexible joint, well
fitted for general motion, and evidently produced by it. The vertebrae are
proccelian when lateral motion is dominant (Serpents); opisthoccelian with
varied motion (Dinosaur cervicals).
(4.) Saddle vertebre (Birds); the highest type; a very strong and free
articulation, especially adapted to motion in a vertical plane, and mainly
due originally to its predominance.
In considering the mode of life, and habits of Ichthyornis, many
important suggestions may be derived from its structure, as well as from
the localities where the remains are found. The sharp cutting teeth
of Ichthyornis prove, beyond a doubt, that it was carnivorous; its great
powers of flight, long jaws, and its recurved teeth suggest, moreover, that
it captured its prey alive. Its food was probably fishes, as their remains
are found in great abundance mingled with those of Ichthyornis. These
fossils occur in the bed of the old Cretaceous ocean in which Hesperornis
swam. Both of these birds were clearly aquatic in habit, as shown by
various points in their structure, already described, and the conditions
under which their remains were deposited. In many respects, Ichthyornis
probably resembled the modern Terns in its mode of life. The powerful
wings and small feet suggest similar habits in flight, and rest. That
Ichthyornis was provided with feathers is proved beyond question by the
tubercles for the attachment of quills on the forearm.
Beside Ichthyornis and its allies, the only other denizens of the air at
present known to have then inhabited the same region were the toothless
Pterodactyles. Ichthyornis doubtless competed with these huge dragons
for the fishes in the tropical ocean, about which they lived.
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CHAPTER. XVII.
CONCLUSION.
Havine now described the more important characters in the structure,
so far as known, of the two groups of Cretaceous Odontornithes, or Birds
with teeth, it remains to consider what relation these birds bear to each
other, and to allied members of the class; and, also, to inquire if the
facts presented throw any light on the profounder question as to the origin
of Birds.
In comparing Hesperornis and Ichthyornis, as the types of their
respective orders, the Odontolee and Odontotorme, the contrast in their
principal characters is as striking as it is unexpected. Hesperornis had
teeth implanted in a continuous groove, a low, generalized character;
with, however, the strongly differentiated saddle-shaped vertebrae. Ichthy-
ornis, on the other hand, had the primitive biconcave vertebrae, and
yet the highly specialized feature of teeth in distinct sockets. Better
examples than these could hardly be found to illustrate one fact brought
out by modern science, that an animal may attain great development in
one set of characters, and at the same time retain other low features of the
ancestral type. This is a fundamental principle of evolution. :
The more superficial characters of the absence of wings and th
strong swimming legs and feet of Hesperornis are in striking contrast, also,
with the powerful wings and diminutive legs and feet of Ichthyornis.
These and other characters, already mentioned, separate the two birds
so widely that a more detailed comparison seems here unnecessary.
; 24 185
186 ODON'VORNITHES,
It would be highly desirable to carefully compare both Ichthyornis
and Hesperornis with Archeopteryx, the still older Mesozoic bird. This
unfortunately cannot be done at present, as the two skeletons of
Archeopteryx, now known, have not yet been fully described, nor even
prepared for examination by removal of the matrix. That Archeopteryx
belongs to the Odontornithes, the writer fully satisfied himself by a personal
examination of the well known specimen in the British Museum. This
examination was made in 1878, several years after the writer had become
familiar with the American forms of toothed birds. The teeth seen on the
same slab with this specimen of Archeopteryx, and referred to it by
Evans, although imperfectly preserved, agree so closely with the teeth of
Hesperornis, that the writer identified them at once as those of Birds, and not
of Fishes. It has since been announced that the specimen of Arche@opteryz,
more recently found in Germany, also possessed teeth, although only two
of small size were detected. The separate metacarpal bones, and especially
the elongated tail, of Archeopteryx, moreover, remove it widely from the
known American genera of Odontornithes. It will probably be found,
however, that Archeopteryx possessed biconcave vertebra, somewhat like
those of Ichthyornis.
The other Mesozoic birds now known from the deposits of this country,
and the few discovered in Europe, may, some or all of them, have had
teeth, but their remains are too fragmentary to determine this point, or
even their near affinities.
It is an interesting fact that the Cretaceous birds at present known,
some twenty species or more, were all apparently aquatic forms,
which are of course most likely to be preserved in marine deposits,
while the Jurassic Archeopteryx, the only one from that formation, was a
true land bird.
The Birds found in more recent formations all belong apparently to
modern types, and hence present few points for profitable comparison
with the Odontornithes. The existing birds with reptilian characters are
nearly all confined to the Ratite, or Ostrich tribe. These are evidently the
remnants of a very numerous group, once widely extended over different
CONCLUSION. 187
parts of the earth; and it is to the fossil forms of these birds that we must
look eventually for the intermediate types between them and the less
specialized Mesozoic birds.
For the present, at least, it seems advisable to regard the Odontornithes
as a sub-class, and to separate them into three orders, according to the
characters given below. These orders are all well marked, but evidently
are not of equal rank. Archeopteryr is clearly separated much more
widely from both Ichthyornis and Hesperornis than are these two genera
from each other. The free metacarpals and long tail of Archeopteryx are
significant characters. Gegenbaur and Morse have shown, however, that
young birds of existing species have the metacarpals separate, and this is
true for all these birds up to a certain age. Hence this character is of
less importance than the presence of true teeth, since in no recent birds,
young or old, have these been found. The length of tail is perhaps a char-
acter of more value, but even this is a variable feature in modern birds.
Sub-class ODONTORNITHES (or Aves Dentar#), Marsh.
Order Opontotc#, Marsh. |OponrorormM#, Marsh.| Saurur#, Haeckel.
Genus Hesperornis, Marsh. | Ichthyornis, Marsh. Archaeopteryx, von Meyer.
Teeth in grooves. Teeth in sockets. Teeth in ———?
Lower jaws separate. Lower jaws separate. | Lower jaws ———-?
Vertebree saddle-shaped. | Vertebrae biconcave. | Vertebrae ————?
Wings rudimentary. Wings large. Wings small.
Metacarpals wanting. Metacarpals ankylosed, Metacarpals separate.
Sternum without keel. Sternum with keel. | Sternum ——-—?
Tail short. Tail short. Tail longer than body.
That the three oldest known birds should differ so widely from each
other points unmistakably to a great antiquity for the class. Archeopteryz,
Hesperornis, and Ichthyornis, are all true birds, but the reptilian characters
they possess are convergent toward a more generalized type. No Triassic
birds are known, and hence we have no light on this stage of the develop-
ment of the class. They will doubtless be found, however, and, if we may
188 ODONTORNITHES.
judge from Jurassic Mammals and Reptiles, the next classes above and
below Birds, the avian forms of that period would still be birds, although
with even stronger reptilian features. For the primal forms of the bird-
type, we must evidently look to the Paleozoic; and in the rich land fauna
of our American Permian we may yet hope to find the remains of both
Birds and Mammals.
The genera Archeopteryx, Hesperornis, and Ichthyornis, each possessed
certain generalized characters not shared by the others. These characters
were undoubtedly united in some earlier form, and this fact gives us a hint
as to what the more primitive forms must have been, and suggests the
prominent features of the ancestral type.
In the generalized form to which we must look back for the ancestral
type of the class of Birds, we should therefore expect to find the following
characters :
(1.) Teeth, in grooves.
(2.) Vertebrze biconcave.
(3.) Metacarpal and carpal bones free.
(4.) Sternum without a keel.
(5.) Sacrum composed of two vertebree.
(6.) Bones of the pelvis separate.
(7.) Tail longer than the body.
(8.) Metatarsal and tarsal bones free.
(9.) Four or more toes, directed forward.
(10.) Feathers rudimentary or imperfect.
These various characters may indeed have been combined in an
animal that was more reptile than bird; but such a form would be on the
road toward the Birds, rather than on the ancestral line of either Dinosaurs
or Pterodactyles, as feathers were not a character of these groups. With
this exception, all of the characters named belong to the generalized
Sauropsid, from which both birds and the known Dinosaurs may well
have descended. An essential character in this ancestral type would be a
free quadrate bone, since this is a universal feature in Birds, and only
partially retained in the Dinosaurs now known.
CONCLUSION, 189
The Birds would appear to have branched off by a single stem, which
gradually lost its reptilian characters as it assumed the ornithie type, and
in the existing Ratitae we have the survivors of this direct line. The lineal
descendants of this primal stock doubtless early attained feathers and warm
hlood, but, as already shown (p. 114), never acquired the power of flight,
The volant birds doubtless separated early from the main avian stem,
probably in the ‘Triassic, since, in the formation above, we have
Archeopteryx, with imperfect powers of flight.
This power of flight probably originated among the small arboreal
forms of reptilian birds. How this may have commenced, we have an
indication in the flight of Galeopithecus, the flying squirrels (Pteromys),
the flying lizard (Draco), and in the flying tree-frog (Rhacophorus). In the
early arboreal birds, which jumped from branch to branch, even rudi-
mentary feathers on the fore limbs would be an advantage, as they would
tend to lengthen a downward leap, er break the force of a fall. As the
feathers increased, the body would become warmer, and the blood more
active. With still more feathers, would come increased power of flight,
as we see in young birds of to-day. A greater activity would result in
a more perfect circulation. A true bird would doubtless require warm
blood, but would not necessarily be hot-blooded, like the birds now living.
The short wings and clumsy tail of Archeopteryx were quite sufficient
for short flights from tree to tree, and if the body were essentially naked,
as now supposed, we have in this Jurassic form an interesting stage in
the development of birds before full plumage was attained. Whether
Archeopteryx was on the true Carinate line cannot at present be determined,
and this is also true of Ichthyornis ; but the biconcave vertebrz of the latter
evidently suggest that this form was an early offshoot. It is probable that
Hesperornis came off from the main Struthious stem, and has left no
descendants.
These three ancient birds, so widely different from each other, and from
all modern birds, prove beyond question the marvelous diversity of the
avian type in Mesozoic time; and also give promise of a rich reward to
the explorer who successfully works out the life-history of allied forms,
recorded in ages more remote.
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Cervical and Dorsal Vertebre of HESPERORNIS REGALIS Marsh.
All Figures Natural Size. Page.
Fic, 1.—Seventeenth or last cervical vertebra; lateral view, seen from the left. Fypepephyas
imperiect, ---3-—2- <= 23-3 === nn yes oe a ee
la —Superior viey.
14 —Anterior view.
le —Inferior view.
Fic. 2.—Eighteenth vertebra; first dorsal, lateral view, seen from the left. Neural spine
: SVC UOTE Cg eel a
la —Superior view. Right diapophysis removed, _
2b —Anterior view.
2¢e —Inferior view. Left diapophysis removed,
Fic. 3.—Nineteenth vertebra; second dorsal, lateral view, seen from the left,.---.---------..
3a —Superior view.
36 —Anterior view.
3c —Inferior view
Fic. 4.—Twentieth vertebra; third dorsal, lateral view, seen from the left,.._-. -..-._--._-. .- 48
4a —Superior view.
4b —Anterior view. t
4¢ —Inferior view.
Fic. 5.—Twenty-first vertebra; fourth dorsal, lateral view, seen from the leit, ----..-. -.------ 507
5a —Superior view.
56 —Anterior view.
5c —Inferior view.
Fic. 6.—Twenty-second vertebra; fifth dorsal, lateral view, seen from the left,_--...---------- 53
6a —Superior view.
6 —Anterior view.
6c —Inferior view.
Fic. 7.—Twenty-third vertebra; sixth dorsal, lateral view, seen from the leit, ....-------.-.-- 55
7a —Superior view.
7b —Anterior view. Neural spine somewhat too short.
, Te —Inferior view.
‘
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.
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Fic.
Fic.
Fic.
Fic.
Itc.
Fia.
Fic.
PLAWH,. Va.
ODONTORNITHES.
Bones of Scapular Arch and Sternum of HESPERORNIS REGALIS Marsh.
All Figures Natural Size.
1.—-Sternum ; lateral view, seen from the left. Outline restored in part from figures on
Plate. Vilj22.- 22... 5-02 24 sobe debe ea weed ese ee ee ee
2°.—Sternum ; ‘inferior views. .52--= =.22.42. 6-22 6262 20 5- oar eee ee ee
3.—Left clavicle; lateral view, seen from the right, -........---.-.----+-.-------------
3a—Inferior end, showing face for cartilaginous union with its fellow. (Compare
Plate VIII, Fig. 8.)
4-—Right coracoid ; external surface, -.<.-—- -- a2 a> oor en nn ses oe ee en
5.—Right coracoid ; lateral view, seen from the right, -----------.----.-------.--------
6:—hightcoracoid's ‘inner'!suriace,-.- 42. -- oa a2 oe eee ee
7.—Left scapula; external surface. (See also Plate VIII, Figs. 5, 6 and 7,)--.---.---. oe
Page.
60
60
61
= HESPERORNIS REGALIS, Marsh
PLATE VII.
PEAT H var
ODONTORNITHES.
Sternum, Coracoid and Clavicle of HErSPERORNIS CRASSIPES Marsh.
All Figures Natural Size.
, 1.—Sternum; lateral view, Seen from the left, ---..---5---- 2-5 S22
. 2.—Sternum; anterior view;-..--=-<=-22- 526 2-22 - ens se ae eee a ee ee
. 3.—Sternum ; inferior view, showing entire absence of keel, ----.-.----- ----------------
pds RNG COTACOIG ss sIMTAer ENEOG et re
» Det Glavaole’s (seen\fromn DOV Gey. cre ence we eee
HESPER
RNIS CRASSIPES, Marsh.
VIII.
PLATE Aseria
ODONTORNITHES.
Humerus, Scapula and Shoulder-girdle of HESPERORNIS REGALIS Marsh.
All Figures Natural Size.
Fic. 1.—Right humerus; inner surface,--------------------------------------------------
Fie. 2.—Right humerus; radial side, . .....--.--.------- -=--+-------------------=-== <==5
2a —Proximal end.
Fic. 3.—Right humerus; ulnar side,_.----. -..-------.---. ----------+---- ---- ---- --------
& —Distal end, showing entire absence of articulation.
Fic. 4.—Right humerus; external surface, .------.--- ----~--- ---- ---= --== -=-- -=- - «2 =~ == ==
Hie. 5.—left scapula; anterior view, ----—--—— ~~
Fic. 6.—Left scapula; inner surface, -- -- -- -- ---- ~~ 0 - <3 -- n n
6a —Proximal end.
Fic. 7%,—Left scapula; posterior view, --- ---- ---- --------e-ee-an= Semcon ans. = oe eee
Fic. 8.—Sternum and scapular arches, restored ; front view,.--- .---------------------------
st —Sternum.
cl —Clavicle.
ce —Coracoid.
s —Scapula.
hk —Humerus.
Note.—In figure 8, portions of the scapular arch are diminished in size by the perspective. This is especially
noticeable in the humerus.
62
62
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RORNIS
HESPE
Fic.
Fic.
Fic.
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Fic.
Fic.
Fie.
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Fic.
Fic.
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Fic.
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Fic.
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PLATE £2
ODONTORNITHES.
Ribs and Uncinate processes of IIESPERORNIS REGALIS Marsh.
All Figures Watural Size.
1.—First articulated rib; from the left side, exterior view, ------------ ------------ ----
2,—Second articulated rib; “ ss s ee ee en es ha ee es SS
3.—Third articulated rib; “ § SS Oe 3 oe ee ee ee
u—Articular surface for first uncinate process.
4,—Fourth, or first true dorsal, rib; from the left side, exterior view, -. ---- ---- --------
5.—Fifth rib; from the left side, exterior view,--------- -.- -- -2-- === -=-- --=- .--=--<=
6.—Sixth rib; “ £ is eae dic ut soeneer = soe ee Soar
7.—Seventh rib; “ a es EEE Se ee a ee ae on,
8.—Eighth rib; “ « ee eR o's eee eee
u—Articular surface for last uncinate process.
9.—Ninth rib; from the left side, exterior view, .-..--- ---------.--. ----------------
10.—First uncinate process; from left side, articulating with third rib at the point
MOTE 24; @XTOLLOL, VIC Ws) sores oe ae ee ea ae!
11.—Second uncinate process; from left side, exterior view, --._.------- .--- .------- ----
12.—Third uncinate process; “ Ny ss SSG Anan 3 oe ee Ree as x
13.—Fourth uncinate process; “ a < $6. te Soest as pe aslos —
14.—Fifth uncinate process ; as ss s CON ee ee Ee Bs Saree =
15.—Sixth uncinate process ; se S ss A aie ee erie oe ces
16,—First sternal rib; articulating with first true dorsal rib, from left side, exterior view, --
17.—Second sternal rib; from left side, external view, .-------- ---- Peer a aes
18.—Third sternal rib; ir a & SC ae Se ee a Re IE we re
19.—Fourth sternal rib; “ BS cs ON SE Ge ge an ee
20.—Fifth sternal rib ; si i: - SE ne ee ee eee p = < «bec
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PLAT Ha 41a-
ODONTORNITHES.
Caudal vertebre of HrESPERORNIS REGALIS Marsh.
All Figures Natural Size. Page.
1.—First free caudal vertebra; lateral view, seen from the left. Neural spine restored, -. 78
1@ —Superior view.
16 — <== ===
3a—Proximal end of femur.
. 4.—Left femur ; fibular side, ... 2 - == - 52-8 32 = ee ee
88
88
PLATEH XIV.
PLAS, _Sceye
ODONTORNITHES.
Tibia of HrsprrorNis REGALIS Marsh.
Natural Size. Page.
Kray 1. Left tibia; anterior wiew;e> ce osc ee ee ae Se ee ee ee
Fic. 2.—Left tibia; exterior surface, showing fibular ridge, -.....-.-------.---------------- 90
2a—Proximal end.
IBxGiao;— ete tibial: posterior View, seeo ese a ee ee eee ea eet
8a—Distal end.
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PLATE XV.
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PLATE Xe
ODONTORNITHES.
Patella and Fibula of HrEsPERORNIS REGALIS Marsh.
All Figures Natural Size. Page
Wig. 1:—Left patellas, anterior View), 222. 2-2 --a5 -2-- 55> oo eae ee oe ne eee ae -
Wie. 2.—Left patella; lateral view, seen from theileft, = .--2 22-2222 cso -2 -ne- a= = eee ee
Fic. 3.—Left patella; lateral view, seen from the right,.....-----. ------.----.---. .------ 93.
Bia, 4.—Left fibula; anterior view, 2.22. <2522e--se= 2 5 =o eo ee ee
Ic. 5.—Left fibula; exterior view,,= 2--==
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ODONTORNITHES.
Femur and Tibia of IcHTHYORNIS DISPAR Marsh.
All Figures twice Natural Size. Page.
Kura, 1.—Left femurs ‘anterior, or superior, View, =2.- -62-.25- ----2- =o steep oe 171
la —Distal end.
Kixe.2;— Left femurs inner, or tibial, surface, 2 = 222./5.0 3 -S ace soe- ss cee eae eee
Frg..8:— ett femur; posterion view; y-.~-=.=2- 5626... 28 el a aoe Pee eee
3a —Proximal end.
Fira. -4.—Heft femur; outer, or fibular; surfacos- 2) 2-228. 2. SP, ee
Fic, 5.—Right tibia; proximal portion, anterior view,.---. -------------------- ---- -------- 172
5’ —Distal half; approximately in position, anterior view.
5a—Proximal end.
Fic. 6.—Right tibia; proximal portion, exterior view, _--..-.-.------------- ------------- 12
6’ —Distal half; approximately in position, exterior view.
Fic. 7.—Right tibia; proximal portion, posterior view, ----------~- = =-- -----se--=-<--sess—== 172
7’ —Distal half; approximately in position, posterior view.
7’a—Distal end.
Fie. 8.—Right tibia; proximal portion, inner view, -.-.-.-.--~----. ----------------s=----. 178
8’ —Distal half; approximately in position, inner view.
PAA) 2AxkSnN
ODONTORNITHES.
Restoration of ICHTHYORNIS DISPAR Marsh.
Natural Size. Page.
In this restoration, the shaded portions represent the parts preserved of the type specimen,
(No, 1450, Yale College Museum). The portions in outline are taken in part from other specimens
but mainly from the skeleton of a Tern, (Sterna regia Gambel.) -------- ---- --------------»----- 17
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PLA VY iF
ODONTORNITHES.
Cervical and dorsal Vertebrz of IcuTHYORNIS vicroR Marsh.
All Figures twice Natural Size,
Page.
1.—Atlas and axis, or first and second cervical vertebre; lateral view, seen from the left,. 127
la—Superior view.
1—Anterior view
1c—Inferior view.
1d—Posterior view.
2.—Third (?) cervical vertebra; lateral view, seen from the left, ......-.----------------
2a—Superior view.
2b—Anterior view.
2ce—TInferior view.
2d—Posterior view.
3.—Posterior cervical vertebra; lateral view, seen from the leit,...---------------------
38a—Superior view.
8b—Anterior view.
8c—Inferior view.
38d—Posterior view.
4,—Anterior dorsal vertebra; lateral view, seen from the left, .-.~-----------------------
4a—Superior view.
4b—Anterior view.
4c—lInferior view.
4d—Posterior view.
. 5.—Posterior dorsal vertebra; lateral view, seen from the left,
5a—Superior view.
5b—Anterior view.
5c—Inferior view.
5d—Posterior view.
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ODONTORNITHES.
Sacrum of APpATORNIS, and Caudal Vertebre of IcHTHYORNIS.
All Figures twice Natural Size. Page.
Fic. 1.—Sacrum of Apatornis celer Marsh; lateral view, seen from the left, anterior end imperfect, 162
1a—Superior view. :
10 —Inferior view.
le—Posterior view.
Fic. 2.—T'irst of seven consecutive caudal vertebrae of Jchthyornis victor Marsh; lateral view,
seen Trom ‘the left,=..:- 52 2 42s: 22222 soe Saas ee a eee eee 165
2a—Superior view.
2b—Anterior view.
2e—Inferior view.
2d—Posterior view.
Fic. 3.—Median caudal vertebra; lateral view, seen from the left, _------------------------- 166
3a—Superior view.
3—Anterior view.
3¢e—Inferior view.
8d—Posterior view.
Tic. 4.—Median caudal vertebra; lateral view, seen from the left, ...----.- ---------------- 166
4a—Superior view.
4b—Anterior view.
4ce—Inferior view.
4d—Posterior view.
Vic. 5.—Posterior caudal vertebra; lateral view, seen from the left,_.... ..------------------ 167
5a—Superior view.
5b—Anterior view.
5¢e —Inferior view.
5¢—Posterior view.
Tic. 6,—Posterior caudal vertebra; lateral view, seen from the left, ---.-.-.----.------------ 167
G6a—Superior view.
¢6+—Anterior view.
6c —Inferior view.
6d—Posterior view.
Vic. 7.—Posterior united caudal vertebre; lateral view, seen from the left, ..........-.------ 167
Ta—Superior view.
7b—Anterior view.
7c—Inferior view.
7d—Posterior view.
Norn,—The caudal vertobre figured on Plate XXVIII are consecutive, and were found with the pelvis represented
on Plate XXX, figures 2 and 3,
Ic. 1.—Left scapula of Apatornis celer Marsh; exterior view, .---.-----------------------
la —Proximal end.
Fic. 2.—Left scapula of Apatornis celer ; anterior, or superior, view, -----------------------
Fic. 8.—lLeft scapula of Apatornis'celer; inner view, ----<- =-- --2 == ==s5 a2 eee eae eee
Fic. 4.—Left scapula of Apatornis celer ; posterior, or inferior, view, -------------.---------
Fic. 5.—Right coracoid of Apatornis celer; anterior view, --------.-----------------------
5a@ —Sternal end.
Fic. 6.—Right coracoid of Apatornis celer ; posterior view, ------.----------.---------«---
Fic. 7.—Upper portion of clavicle of Apatornis celer ; exterior view, -.-----------.---------
7a— Posterior view.
7b— Inner view.
7c— Anterior view.
Fie. 8.—Sternum of Apatornis celer; inferior view, ------------------------------------=- ;
Fic. 9.—Left scapula of Zchthyornis victor Marsh ; exterior view, ---. -----.-----------------
9a—Proximal end.
Fig. 10.—Left scapula of Zchthyornis victor ; anterior, or exterior, view, --------.-------.----
Fic. 11.—Left scapula of Zchthyornis victor ; inner view, .--. ------------------«-------~----
Itc, 12.—Left scapula of Zchthyornis victor ; posterior, or inferior, view, ----------~---------
Fic, 13,—Left coracoid of Ichthyornis victor ; posterior view, ----------------------------+-
Fic. 14.—Left coracoid of Jchthyornis victor ; exterior view, --- ---- -- mylene ee
Fic. 15,.—Left coracoid of Zchthyornis victor ; anterior view,-------.---------------:-------
15a—Scapular end.
Fie, 16.—Left coracoid of Ichthyornis victor ; inner view, -.--.--~.----.--------------------
PLAGE. Seis
ODONTORNITHES.
Sternum and Scapular Arch of APATORNIS and JcHTHYORNIS.
All Figures twice Natural Size.
147
141
144
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ODONTORNITHES.
Wing bones of APATORNIS and IcHTHYORNIS.
All Figures twice Natural Size. Page. 2)
Fic. 1.—Left radius of Apatornis celer Marsh ; proximal portion, inner view, ----------.--.-- 152
Fic. 2.—Left radius of Apatornis celer ; proximal portion, inferior view, -----------------_-- 152
Fic. 3.—Left radius of Apatornis celer ; proximal portion, exterior, or ulnar, surface,......... 152
3a —Proximal articular surface.
Fic. 4.—Left radius of Apatornis celer ; proximal portion, superior view, ------------------- 152
Fic. 5.—Left radial carpal of Apatornis celer ; anterior view, ----------------------------- 153
5a —Inner view.
56 —Posterior view.
5e —Lxterior view.
5d —Superior view.
5e —Inferior view.
Fic. 6.—Left ulnar carpal of Apatornis celer ; anterior view, .-.---.-----------------..----- 154
6a —Exterior view.
6b —Posterior view
6c —Inner view.
6d —Inferior view.
6e —Superior view.
Fic. 7—Right humerus of Jchthyornis victor Marsh; immer, or posterior, view, --...-.-...... 149
Fic. 8.—Right humerus of Zchthyornis tener Marsh; distal portion. Inner, or posterior, viey;, 149
8a@ —Ulnar surface.
sb —Outer or anterior view.
Se —Radial surface.
8d —Distal end.
Fic. 9.—Left radius of Jehthyornis victor Marsh; proximal portion, inner view, -- ---- -- ---- 151
9a —Inferior view.
9b —Exterior, or ulnar, surface. ‘
9¢ —Superior view.
9d —Proximal end.
Fria. 10.—Left radius of Ichthyornis victor ; distal portion, inner, or anterior, view, -------- -- 151
10a—Inferior view.
10)—Exterior, or ulnar; surface.
10e—Superior view.
10¢—Distal end.
Fic. 11.—Left ulna of Jchthyornis validus ; exterior view, -..---..--.-----------.---------- 162 es
Fic. 12.—Left ulna of Ichthyornis validus ; superior view-.---. .--- .--. ----.--- ------.---- 152
12a—Proximal end.
Fic. 13.—Left ulna of Jchthyornis validus ; inner, or radial, surface, ................-....... 152
Fig. 14.—Left ulna of Zchthyornis validus ; inferior view,.-..--.---.--.-.---.--------.------- 152
14a—Distal end.
10
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PLAT 2 xa
ODONTORNITHES.
Wing bones of APATORNIS and IcHTHYORNIS.
All Figures twice Natural Size.
Fic. 1.—Right metacarpal of Apatornis celer Marsh; exterior view,-..-..-.----------------
Fic.
Fic.
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1a —Distal end.
2.—Right metacarpal of Apatornis celer ; superior, or ulnar, surface, __.__._..-..--.-----
3.—Right metacarpal of Apatornis celer ; inner view, ---.----------------------------
38a@ —Proximal end.
4.—Night metacarpal of Apatornis celer ; inferior, or radial, surface, ._...._..----------
5.—Proximal phalanx of second digit of Apatornis celer ; from the right wing, inferior,
or radial surface, 222 5-2 422552 30.cn5.20 eee oe eee ee
5a@ —Distal end.
6.—Proximal phalanx of second digit of Apatornis celer ; exterior view,_.-.---.------ -
7.—Proximal phalanx of second digit of Apatornis celer ; superior view,--------.-------
7a —Proximal end.
8.—Proximal phalanx of second digit of Apatornis celer; inner view, -..---------------
9.—Second phalanx ot second digit of Apatornis celer ; from the right wing, inner view, -
9a —Distal end; with outline of proximal end.
10.—Second phalanx of second digit of Apatornis celer ; inferior, or radial, surface, -----.-
11.—Second phalanx of second digit of Apatornis celer ; exterior view,-.--.--.----------
11a—Proximal end.
12.—Right metacarpal of Iehthyornis victor Marsh; exterior view, ....-.---. .----------
12a—Distal end.
13.—Right metacarpal of Iehthyornis victor ; superior, or ulnar, surface,_...--.---------
14.—Right metacarpal of Ichthyornis victor ; inner view,..----.--------.--------------
14a—Proximal end.
15.—Right metacarpal of Ichthyornis victor ; inferior, or radial, surface, ...--.---- ae
16.—Proximal phalanx of second digit of Ichthyornis victor ; from the right wine, inferior,
or radial, surficg,. soon 5-0 sae nee ee oe aan ee rr’
16a—Distal end.
17.—Proximal phalanx of second digit of Zchthyornis victor ; exterior view, .......------
18.—Proximal phalanx of second digit of Jchthyornis victor ; superior, or ulnar, surface,
18a—Proximal end,
19.—Proximal phalanx of second digit of Zchthyornis victor ; inner view, ....-----.-.--
ee
4)
_—
PLATE XXXTI.
PLAT eis
ODONTORNITHES.
Pelvis of APATORNIS and ICHTHYORNIS.
Twice Natural Size. Page.
Fic. 1.—Pelvis of Apatornis celer Marsh; lateral view, seen from the right, ..--...---------.- 164
il —Ilium.
és —Ischiur~.
pb—Pubis.
af—Acetabular foramen.
a —Ischio-sciatie interval.
6 —Obturator interval.
Fic. 2.—Pelvis of Ichthyornis victor Marsh; superior view, - .----..-.---------------------- Aer |S:
él —Tlium.
is —Ischium.
pb—Pubis.
s —Sacrum.
Wie. 8.—Pelvis of Ichthyornis victor ; inferior view,----------------. ---------------------- 163
s —Sacrum restored in part from sacrum of Jehthyornis dispar, (Pl. XXII, fig. 7.)
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PLATE Arr
ODONTORNITHES.
Leg bones of APATORNIS and IcHTHYORNIS.
All Figures twice Natural Size, Page.
Fic. 1.—Right tibia of Apatornis celer Marsh; anterior view. Proximal portion wanting, ---. 173
Fic. 2.—Right tibia of Apatornis celer ; exterior view, -----. -.--. -------- ---------------- 118
Fic. 38.—Richt tibia of Apatornis celer ; posterior view, ---- ---- -------------------- ------ 173
8a —Distal end.
Fic. 4,—Right tibia of Apatornis celer ; inner view, -- ------------------------------------ 173
Fic. 5.—Right fibula of Apatornis celer ; posterior view, -- -------------------------.-.--- 174
Fic. 6.—Right tibia of Zchthyornis victor Marsh; anterior view, ---------. .---------------- 172
Fic. 7.—Right tibia of Ichthyornis victor ; posterior view, ----------.----------------.---- 172
Fie. 8.—Phalanx of Zchthyornis victor ; superior view, ----------------------------------- 176
8a —Proximal end.
8b —Lateral view.
8¢e —lInferior view.
8d —Lateral view.
8e —Distal end; with outline of proximal end,
Fic. 9.—Right tarso-metatarsal of ZJehthyornis victor ; anterior View,. ---.---.-------------- 174
9a —Distal end.
Fic. 10.—Right tarso-metatarsal of Ichthyornis victor ; exterior view,--.-------------------- 174
Fic. 11.—Right tarso-metatarsal of Ichthyornis victor ; posterior view,----.-------.---.----- 174
lla—Proximalend. ,
Fic. 12.—Right tarso-metatarsal of Zehthyornis victor ; inner View, -----.-------------- eRe So fy: *
PLATE XXXII
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PEATE XXXIV.
PLAT HEH Seki
ODONTORNITHES.
Restoration of IcHTHYORNIS VICTOR Marsh.
Page.
Natural Size.
In the restoration of this species, the shaded portions represent the parts preserved of the type
specimen, (No. 1452, Yale College Museum), as well as of other individuals from the same region, and
the same geological horizon, The portions in outline are taken in part from the type of Ichthyornis
dispar, (Plate XXVI), and completed from the skeleton of a Tern, (Sterna regia Gambel) .........- 177
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