Transcriber's Notes:
Underscores "_" before and after a word or phrase indicate _italics_
in the original text.
Equal signs "=" before and after a word or phrase indicate =bold=
in the original text.
Small capitals have been converted to SOLID capitals.
Illustrations have been moved so they do not break up paragraphs.
Typographical errors have been silently corrected but other variations
in spelling and punctuation remain unaltered.
Vol. I. JULY, 1892 No. 1.
THE KANSAS UNIVERSITY QUARTERLY
COMMITTEE OF PUBLICATION
E. H. S. BAILEY F. W. BLACKMAR
W. H. CARRUTH C. G. DUNLAP
E. MILLER S. W. WILLISTON
V. L. KELLOGG, _Managing Editor_
CONTENTS
KANSAS PTERODACTYLS, PART I. _S. W. Williston_
KANSAS MOSASAURS, PART I. _S. W. Williston and E. C. Case_
NOTES AND DESCRIPTIONS OF SYRPHIDAE, _W. A. Snow_
NOTES ON MELITERA DENTATA GROTE, _V. L. Kellogg_
DIPTERA BRASILIANA, PART II. _S. W. Williston_
PUBLISHED BY THE UNIVERSITY
LAWRENCE, KANSAS
_Price of this number, 50 cents_
Entered at the Post-office in Lawrence as Second-class matter
JOURNAL PUBLISHING HOUSE,
LAWRENCE, KANSAS.
1892.
KANSAS PTERODACTYLS.
BY S. W. WILLISTON.
PART I, WITH PLATE I.
The first American species of the singular group of extinct Mesozoic
reptiles variously know as Ornithosaurs, Pterosaurs or Pterodactyls was
described by Marsh from a fragmentary specimen obtained in 1870, by the
Yale College Expedition in Wallace County, Kansas. About a dozen other
specimens were obtained by a similar expedition the following year in
charge of Professor Marsh, or by Professor Cope, and were described by
these authors shortly afterward. By far the largest number of known
specimens, however, other than those in the Kansas University Museum,
were obtained during the years 1874, ’75, ’76 and ’77 by parties of
which Professor Mudge, Dr. H. A. Brous, E. W. Guild, George Cooper and
myself were the members, and it was from these specimens that most
of the published characters were derived. Many of these specimens
are necessarily fragmentary ones, still the material now in the Yale
College Museum is ample to elucidate everything of interest concerning
these animals.
During the past few years, the Museum of Kansas University has been
enriched by a series of excellent specimens of these animals, obtained
from the same regions, specimens that permit the solution of most of
the doubtful characters and throw not a little light on the affinities
of the Kansas forms.
The species hitherto named are as follows:
PTERANODON.
_Pteranodon_ Marsh, Amer. Journ. Sci. xi, p. 508,
June 1876; and xii, p. 479, Dec. 1876; xxiii, p. 253,
April, 1882; xxvii, p. 423, May, 1881; Williston,
Amer. Naturalist, xxv, p. 1174, Dec. 1891
=Pteranodon occidentalis.=
_Pterodactylus Oweni_ Marsh, Amer. Journ. Sci. i, p.
472, June 1871, Sep. p. 16 (nom. preoc).
_Pterodactylus occidentalis_ Marsh, Amer. Journ. Sci.
iii, p. 242, April 1872, Sep. p. 1; Cope, Cretac.
Vert. p. 68, pl. vii, ff. 5, 6.
_Ornithocheirus harpyia_ Cope, Proc. Amer. Phil. Soc.
1872, p. 471 (Cope).
This species was originally based upon the distal end of two
wing-metacarpals, and teeth. In the following year, a fuller
description was given of additional remains referred to the same
species and renamed _P. occidentalis_.
=Pteranodon ingens.=
_Pterodactylus ingens_ Marsh, Amer. Journ Sci. iii, p.
246, April 1872, Sep. p. 6.
_Pteranodon ingens_ Marsh, Amer. Journ. Sci. xi, p.
508, June 1876.
This species is based upon various bones of the wing-finger of several
individuals, and three teeth.
=Pteranodon umbrosus.=
_Ornithocheirus umbrosus_ Cope, Proc. Amer. Phil. Soc.
1872, p. 471.
_Pterodactylus umbrosus_ Cope, Cret. Vert. p. 65, pl.
vii, ff. 1-4.
Marsh (Amer. Journ. Sci. xii, p. 480, Dec. 1876) says this name is a
synonym of _P. ingens_, published two days earlier. As this synonymy is
not certain, and as Cope’s species has been figured, I am not ready to
accept his views.
=Pteranodon velox.=
_Pterodactylus velox_ Marsh, Amer. Journ. Sci. iii, p.
247, April 1872, Sep. p. 8.
Based upon the distal end of the right metacarpal of the wing-finger,
and the proximal extremity of the adjoining first phalanx, two
uncharacteristic parts of the skeleton, Marsh to the contrary
notwithstanding. It is doubtful whether the direct comparison of the
types will suffice to determine the species with certainty. “Both of
the bones are somewhat distorted by pressure.”
=Pteranodon longiceps.=
_Pteranodon longiceps_ Marsh, Amer. Journ. Sci. xi,
p. 508, June 1875; xxvii, p. 424, pl. xv, May 1884.
Based upon a somewhat defective skull, without other bones.
There is no evidence whatever that the species is distinct from the
preceding.
=Pteranodon comptus.=
_Pteranodon comptus_ Marsh, Amer. Journ. Sci. xi, p.
509, June 1876.
Based upon wing-bones of three individuals. The description is meagre.
=Pteranodon nanus.=
_Pteranodon nanus_ Marsh, Amer. Journ. Sci. xxi, p.
343, April 1881.
Based upon various remains of one individual; the humerus, alone, is
recognizably described.
NYCTODACTYLUS.
_Nyctosaurus_ Marsh, Amer. Journ. Sci. xii, p. 480, Dec. 1876. (nomen
preoc.[1]).
_Nyctodactylus_ Marsh, Amer. Journ. Sci. xxi, p. 343, April 1881: ibid.
xxvii, p. 423, May 1884.
[1] This preoccupation rests, so far as I am aware, upon Marsh’s
statement. I can find no evidence of the name having been previously
used.
=Nyctodactylus gracilis.=
_Pteranodon gracilis_ Marsh, Amer. Journ. Sci. xi, p.
508, June 1876.
_Nyctosaurus gracilis_ Marsh, Amer. Journ. Sci. xii,
p. 480, Dec. 1876.
_Nyctodactylus gracilis_ Marsh, Amer. Jour. Sci. xxi,
p. 343, April 1881.
PTERANODON.
=Skull.=
Fragmentary portions of the skull of Pteranodon are not at all rare
in the Kansas chalk; but it is exceedingly seldom that a complete,
or even approximately complete specimen is found. Their great length
and slenderness, together with the extensive pneumaticity of the
bones, render their preservation, as a whole, a thing of great rarity.
Probably the most nearly perfect one yet known is now in the Museum
of Kansas University. It was discovered the past summer by Mr. E. C.
Case, a member of the University Geological Expedition. The specimen
was carefully cleaned on its upper surface, as it lay in the chalk, and
then imbedded in plaster before removal. The surface now exposed was
the under one, which surface is, almost invariably, better preserved
and less distorted than the upper one in these animals. A figure of
this specimen is given in Plate I. The only portion restored is that
indicated by the line in the lower jaw; it is possible that this part
of the symphysis may not be exactly as it is drawn. Other, incomplete,
specimens in the Museum confirm the outlines, except in the occipital
crest, which is not present. As stated by me in the American Naturalist
(_l. c._), the type specimen of _Pteranodon_, also collected by myself,
was incomplete, and the figures of it, as given by Marsh, are faulty.
The elements of the skull are all so firmly united that they can
not be distinguished. There are no indications whatever of a horny
sheath enclosing the jaw, and it is improbable that the covering of
these parts was essentially different from that in the slender jawed
_Pterodactylidae_. In texture, the maxillaries are fine-grained, and
wholly without the vascular foramina found in the corresponding bones
of birds. The bones are composed of two thin and firm plates, separated
by cavities which are bounded by irregular walls of bony tissue. In the
compression from which all the Pterodactyl bones have suffered more or
less, the greater resistance of these walls has caused irregularities
upon both the outer and the inner surfaces. At the borders of the
bones, where the thickness has been greater, the roughening is not
observed.
Seen from above, the skull is narrow, as stated by Marsh; but, contrary
to his statement, there is not a sharp ridge extending along the
upper border. This border is obtuse and rounded, and in the frontal
region, flattened. The sagittal crest is large, but not nearly so
large as it is figured by Marsh, the restored outline of whose figure
is undoubtedly wrong. The texture of the bone forming the crest is
materially different from that of the remaining bones of the skull.
The bone is more roughened, and less firm. There is a well-developed
ring of sclerotic ossifications. In the specimen figured, the separate
plates measure from six to eight millimeters in diameter. They were
not imbricated, as in the Pythonomorpha, but have a similar dense
texture. There is a superior temporal arch, bridging over a small
opening leading downward to the inferior temporal fossa. The following
measurements will give the principal dimensions of this specimen.
Length from tip of premaxillary to occipital condyle 680 millim.
Extreme length of skull 780
Extent of crest beyond orbit 145
Greatest diameter of orbit 65
Antero-posterior diameter of nasal opening 135
Length of quadrate 120
Width of lower jaw at articulation 22
=Pubis.=
In a previous paper on the anatomy of _Pteranodon_,[2] I stated that
I had never seen the so-called “prepubic bones.” Since that time,
however, an excellent specimen of them has been discovered among
our material. The specimen of which they are a part consists of the
larger portion of the skeleton, and is perhaps conspecific with the
one to which the described pelvis belongs. The figure given herewith
will convey a good idea of their shape. The bones of the two sides
are firmly co-ossified, and have been pressed nearly flat; the figure
represents them as they are spread out in one plane. The bone is
very thin throughout, with a slight thickening at the ischial (_a_)
attachment only. Lying contiguous with the anterior projection, is a
slender ventral rib (_b_). It is possible that the curvature of this
bone may be inward, rather than outward.
[Illustration: FIG. 1.]
[2] Amer. Naturalist, Dec. 1891, p. 1124. In this article the
description of the foot-phalanges should read: “All are slender, except
the second one in the third toe, and the second and third in the fourth
toe, where they are scarcely longer than wide.”
This peculiar structure of the pubis (I believe it represents the
pubis, and not the prepubis), seems to be quite similar to that
which obtains in the genus _Rhamphorhynchus_, and, perhaps also, in
_Pterodactylus suevicus_ (_Cycnorhamphus_ Seeley), and very different
from that found in other species of _Pterodactylus_.
The principal measurements of the above described specimen are as
follows:
Antero-posterior expansion 40 millim.
Length of symphysis 14
Expanse of the united bones, as flattened 90
Width of ischial process 11
NYCTODACTYLUS.
The type species of this genus was described as follows by its author
(loc. cit. supra):
“One of the smallest American species yet found is
represented in the Yale Museum by several bones of the
wing, a number of vertebrae and the nearly complete
pelvis. The wing-bones preserved are elongated and very
slender. The pelvis is unusually small, and there are five
vertebrae in the sacrum. The last of the series indicates
that the tail was short. The following are the principal
measurements of this specimen:
Length of ulna 187 millim.
Length of metacarpal of wing-finger 300
Antero-posterior diameter of outer condyle at distal end 15
Transverse diameter of shaft, above condyles 13
Length of first phalanx of wing-finger 347
Extent of five vertebrae of sacrum 57
This species, which may be called _Pteranodon gracilis_, was about
two-thirds the size of _P. velox_ Marsh. It probably measured about ten
feet between the tips of the expanded wings.”
In the December number of the same volume of the American Journal of
Science, he described the genus as follows:
“A second genus of American Pterodactyls is represented
in the Yale Museum by several well preserved specimens.
This genus is nearly related to _Pteranodon_, but may be
readily distinguished from it by the scapular arch, in
which the coracoid is not co-ossified with the scapula. The
latter bone, moreover, has no articulation at its distal
end, which is comparatively thin and expanded. The type of
this species is _Pteranodon gracilis_ Marsh, which may now
be called _Nyctosaurus gracilis_. It was a Pterodactyl of
medium size, measuring about eight to ten feet between the
tips of the expanded wings.”
The specific description of this species rests solely upon the
measurements; the other characters given are not only vague, but are
also common to all the known species. The generic description, as it is
seen, is based upon the structure of the coraco-scapula. It will also
be observed that the characters are not drawn from the type specimen,
as that did not include this part of the skeleton, according to the
author’s statement. Of these two characters, the non-ossification
of the coracoid and scapula is a somewhat doubtful one, as the same
character may or may not occur in allied species, as, for example, in
the species of _Rhamphorhyncus_ (_R. Muensteri_ Goldf.) described by
the author himself. So incomplete and unsatisfactory are the characters
thus given that Zittel, in his Handbuch, dismisses the genus with the
brief remark, “noch unbeschrieben.”
Nevertheless, from the peculiar form of the scapula, and from my
recollection of the specimens upon which the genus was based, I
believe I have determined with certainty an excellent specimen in the
Snow Museum of Kansas University as a member of it, and here give a
sufficiently complete description to place the genus on a more secure
foundation.
This specimen was collected by Professor E. E. Slosson, of Wyoming
University, while a member of my party in western Kansas the past
season. It was partly exposed upon a gently sloping surface of firm
yellow chalk on the Smoky Hill river, in the vicinity of Monument
Rocks. Originally, the nearly complete skeleton must have been
preserved, but a number of the bones had been either wholly or
partially washed away, in some cases leaving their imprint in the
chalk. The bones uncovered, and now lying upon the chalk slab nearly
in their natural relations, are a humerus, both radii and ulnae, a
pteroid, the two carpals of one wrist, both wing metacarpals, a first
and a last wing phalanx, both coraco-scapulae, the posterior part of
the lower jaws, ilium, femur, sternum, numerous ribs and vertebrae. The
two coraco-scapulae lie with their scapular ends nearly touching, and
their coracoid ends separated by a space equivalent to the width of the
sternal articulation. The two elements appear to have been imperfectly
united and were probably not co-ossified. The inferior border of the
coracoid, near the humeral articulation, has a greater expansion than
is found in _Pteranodon_; its shaft is more rounded and less rugose,
lacking especially the strong muscular markings upon the external
surface. The articular surface does not appear to differ materially
from that in _Pteranodon_. The scapula is of nearly the same length
as the coracoid, but is much less stout. It is a thin, spatulate
bone, slightly expanded at the distal extremity, where the margin is
rounded, and without the characteristic oblique articular facet. It
has no supra-glenoid expansion or process on the posterior proximal
border, but has its margin nearly straight or gently concave from the
articulation to its extremity. The space included between the bones
of the two sides as they lie is a nearly regular, oval one, measuring
ninety-five millimeters in its greater, forty-five in its lesser
diameter.
The sternum lies at a little distance from the coraco-scapulae. It is
an extremely thin bone, with a stout anterior, styliform projection,
at the base of which, on either side, looking upward and outward,
is the articular, trochlea-like surface for the sternal end of the
coracoid. The width between these articular surfaces measures fifteen
millimeters; the length of the process in front of the articulations
is twenty-five millimeters. Immediately posterior to the articular
surfaces, the bone expands nearly at right angles to the longitudinal
axis to a width of about sixty millimeters. The thin lateral margins
are nearly parallel with the longitudinal axis, and show three shallow
emarginations between the four costal articular projections. The
hind angles are nearly rectangular. The bone, as preserved, is only
shallowly concave, and shows no true keel, though a more pronounced
median convexity towards the front doubtless subserved the function of
a carina in part.
The left humerus lies in position, and is especially characterized by
its enormous deltoid crest (radial crest of Marsh), though otherwise
slender. This crest is further removed from the head of the bone
than is the case in species of _Pteranodon_. It is directed somewhat
downward, and has its distal, gently convex, border about twenty-five
millimeters in extent, while the width of the process midway between
the extremity and the base measures but sixteen millimeters. The
bicipital crest is also prominent. The bone is relatively shorter than
in _Pteranodon_.
The humerus, as will be seen from the above description, and from
the measurements given below, is remarkably like the same bone in
_Pteranodon nanus_, as described by Marsh (_l. c. supra_), and but
a little larger. In _P. nanus_, however, the coracoid and scapula
are said to be firmly co-ossified, and the scapula has of course a
different structure.
The skull has been, unfortunately, almost wholly washed away, a
fragment of the cranial wall and the posterior part of the lower jaws
alone remaining. It is impossible, hence, to say much concerning this
part of the anatomy. The lower jaws show a different structure from
that in _Pteranodon_. As they lie in their natural position, the width
at the condyles is about twenty-four millimeters. The angular is less
produced posterior to the articulation than in _Pteranodon_, indicating
a less elongated and less powerful mandibular portion, an indication
further borne out by the slenderness of the rami. The impression in
the chalk shows the symphysis to begin ninety millimeters from the
articulation. The width at this place could not have exceeded sixteen
millimeters; and the entire length of the lower jaws could hardly
have been more than one hundred and twenty-five millimeters. In the
parts preserved, measuring seventy-five millimeters, there are no
indications of teeth; yet it is not impossible that there may have been
teeth in the anterior portion of the dentary, as in some species of
_Pterodactylus_. I hardly think it probable, however.
There are seven cervical vertebrae preserved, apparently the full
complement, as in _Pteranodon_ and other members of the order. They
differ in no especial respect from the corresponding vertebrae of
_Pteranodon_, and, apparently, of _Pterodactylus_. The imperfectly
anchylosed, possibly free, atlas shows three pieces, the odontoid
process and the two slender lateral pieces. The lateral pieces are
entirely free, with a thickened base and a slender, curved upper
portion. The odontoid is gently concave in front, and seems to be
imperfectly ossified with the axis; it occupies the lower part of the
articulation, corresponding to the hypapophysis of the Pythonomorpha.
The axis is the shortest of the remaining vertebrae, and has a well
developed spine. The centrum is strongly convex behind, as are the
remaining centra of the series. The following five vertebrae decrease
gradually in length. The anterior ones have only a thin ridge or plate
for the neural spine; the seventh, however, has a neurapophysis of
some length. They are all, as is usually the case, somewhat distorted
from pressure. The under side is flattened, apparently gently concave
longitudinally, and with a lateral ridge terminating in an obtuse
hypapophysis at each inferior hind angle.
In his discussion of the Pterosauria, Zittel says concerning the
vertebrae: “zwischen oberen Bogen und Centrum ist keine Sutur zu
bemerken.” Handbuch, iii, p. 776. In this he is in error, so far as
the American forms are concerned. It is usually the case in the Kansas
specimens of both genera that the neural arch of the post-cervical
vertebrae is wholly or in part detached from the centrum, showing a
sutural, and not anchylosed union in life. The centra of twelve
vertebrae are preserved, in the present specimen, from the region back
of the neck; in only five of them are the neural arches in any way
attached. Three of these are evidently anterior thoracic, judging from
their structure and the position in which they lie. The shortest of
them, to which was attached a very large rib, and which was lying in
front of the scapulae, may represent the first thoracic vertebra (_a_).
Its centrum is fully as wide as long, is flat on the under surface,
and has a large, stout, horizontal parapophysis near the anterior end.
Just above this process for the attachment of the head of the rib,
and separated by a deep notch, is a much more elongated, horizontal
diapophysis for the tuberculum. The cup of the centrum is shallowly
concave; the transverse, shallowly U-shaped ball is only a little
convex.
Two other vertebrae (_b_), found close by the one just described, and
possibly one or the other contiguous with it, differ remarkably in
having no, or a rudimentary, parapophysial process, and in having the
diapophyses much shorter. It is not impossible that a slight expansion
at the lateral margins of the ball may represent small parapophyses.
In _Pteranodon_ there are at least four vertebrae with dia- and
parapophyses. In the other vertebrae from this region the diapophyses
are yet shorter and the neural spine stouter and broader. The other
centra preserved are all shaped somewhat like the half of a cylinder,
and are a little longer than broad. They have no distinct cup or ball.
In two of them there is a very long, recurved parapophysial process,
as though formed by an anchylosed rib, on each side; they are probably
lumbar vertebrae.
Most of the ribs are very slender; a few are moderately thickened; one
only is very stout; its measurements are given below.
Length of lateral pieces of the atlas 7 millim.
Diameter of lateral pieces at the base 3½
Width of odontoid 4½
Height of odontoid 3
Length of axis 8
Height of axis 15
Length of third cervical vertebra 21
Length of fourth cervical vertebra 20
Length of fifth cervical vertebra 19
Length of sixth cervical vertebra 18
Length of seventh cervical vertebra 17
Height of seventh cervical (about) 15
Length of centrum, anterior thoracic vertebra (_a_) 6
Width of ball (_a_) 8
Expanse of parapophyses (_a_) 14
Expanse of diapophyses (_a_) 26
Width of neural canal (_a_) 3
Length of centrum, anterior thoracic vertebra (_b_) 8
Width of ball (_b_) 10
Expanse of diapophyses (_b_) 17
Height of neural spine (_b_) 20
Width of neural spine (_b_) 5
Length of rib (_c_) 45
Width of shaft (_c_) 5
Distance from center of capitulum to center
of tubercle (_c_) 10
Length of coracoid 50
Antero-posterior diameter, sternal extremity 9
Length of scapula 45
Width of scapula at distal end 15
Length of humerus 80
Width through deltoid crest 24
Least diameter of shaft of humerus 13
Length of ulna 133
Width of ulna at distal extremity 22
Length of radius 130
Width of radius distally 15
Length of wing-finger metacarpal 220
Width of same metacarpal at proximal end 20
Diameter through condyles 15
Transverse diameter of shaft above condyles 10
Length of first phalanx, wing-finger 263
Width of same phalanx at proximal end 24
Width of same phalanx at distal end 15
Width of sternum 67
Length of rib borders 25
Length of femur 75
Diameter of head of femur 5
Diameter of femur through condyles 12
Length of pteroid bone 88
The principal dimensions of this species can be got at with
considerable certainty. Although two of the wing-phalanges and the
bones of the foot are wanting, yet the relative proportions of those
present agree so closely with those of the corresponding bones in
_Pteranodon_, that there can be but little possibility of error in
assuming the same proportions for the missing ones. The position of the
ilium and femur, as also the ribs, show that they hold their natural
relations to the pectoral arch. The tail, alone, can not be got at.
Extreme expanse of wing-bones 2400 mm. 7 ft. 10 in.
Expanse of wings in life, approximated 2000 6 6
Length of head, estimated 150 6
Length of neck 128 5½
Length of trunk 165 6½
Length of leg and foot, outstretched 275 11
But one species has been described from the American Cretaceous smaller
than the present one, _Pteranodon nanus_ Marsh, in which the expanse of
wings is given as not more than three or four feet. In this estimate
the author is certainly in error. The size of the humerus, as given,
is rather more than three-fourths that of the present species, and the
expanse, hence, must be nearly five feet in life, or six feet as the
bones lie outstretched.
As regards the specific determination of the present specimen, there
must necessarily be some doubt until the species already named have
been recognizably described. But three of the existing species can be
taken into account, _N. gracilis_, _P. comptus_ and _P. nanus_. That it
can not be the last, has already been shown. In size, it agrees well
with _P. comptus_, but the other characters throw no light upon the
identity.
The measurements given of the type specimen of _N. gracilis_ show the
size to be materially greater,—a character, however, of subordinate
value—greater slenderness, and a relatively shorter first wing-phalanx.
The relative lengths of wing-metacarpals, wing-phalanx and ulna in _N.
gracilis_ and the present specimen may be expressed as follows:
Length of wing-metacarpal 100 100
Length of first wing-phalanx 115.6 119.5
Length of ulna 62.3 60.4
It will be seen that not a single character has yet been given to
distinguish the genus from _Pterodactylus_, and it is not at all
impossible that it may prove to be the same; its location among the
_Pteranodontidae_ rests solely on the assumed absence of teeth, and
that is a character yet wholly unknown.
The material now in the museum permits a fuller discussion of the
relations and characters of this group of reptiles than has been
hitherto attempted. Originally, they were described as constituting a
new order, a view still held by its author and no one else. Lydekker,
in his Paleontology and Catalogue gives them a subordinal value; Zittel
only a family value, though expressing doubt as to their subordinal
rank.
It seems very probable that the genus _Nyctodactylus_ has no teeth
in the jaws; it agrees in _every other respect_ with the genus
_Pterodactylus_, so far as known. If the genus has teeth it must be
united with _Pterodactylus_. Now, in not a few species of this genus,
the teeth are confined to the anterior end of the jaws, and their
entire absence, unaccompanied by other structural differences, will
hardly constitute an order, or even family.
But, leaving aside _Nyctodactylus_, it is very much of a question
whether the differences between _Pterodactylus_ and _Pteranodon_ are
sufficient to locate them in different families, let alone different
suborders.
The two genera have the following in common: Tail short. Skull with
more or less elongated, pointed jaws, and very small upper and lower
temporal fossae. Narial opening large, confluent with the pre-orbital
foramen. Cervical vertebrae elongated, with rudimentary spinous
processes. Fore and hind extremities, quite alike.
_Pteranodon_ differs from _Pterodactylus_, so far as that genus is
known, in the united coracoscapulae and pubes, both of which characters
are found in _Rhamphorhynchus_.
The sole family characters remaining then, for _Pteranodon_, are,
absence of teeth, a supra-occipital crest, and the articulation of
the upper end of the scapula. Now it seems evident that to place
the pteranodonts in a group equivalent to all the other pterosaurs
is unwarranted, and any classification that will not show the more
pronounced relationships with _Pterodactylus_ is faulty. I would,
therefore, propose the following:
Order Pterosauria.
Family Pterodactylidae, subfamilies Pteranodontinae,
Pterodactylinae.
Family Rhamphorhynchidae.
Family Ornithocheiridae.
As regards the geographical distribution of the Pteranodonts, they
have hitherto been recognized only from Kansas, but I am firmly of the
opinion that they occur in Europe, and, if so, it is very probable that
the name _Pteranodon_ must be eventually given up. In fact, a toothless
form of Pterodactyl was described by Seeley as long ago as 1871,
under the name of _Ornithostoma_. I cannot refer to his description
at present, and can, therefore, give no opinion as to their identity.
It seems certain that the peculiar form of the scapulae and their
vertebral articulation[3] occur among some of the European forms, which
would strengthen the belief that _Pteranodon_ is also an European genus.
[3] The specimens in which I have seen the vertebral articulation show
no co-ossification of the vertebrae: the facet for articulation being
placed above the spines, and apparently formed by ossified ligaments.
In view of the above, the practice of the American text-books in
Geology in introducing generic names of characteristic fossils as names
of the geological horizons whence they come, is very reprehensible, in
my opinion. Even the late edition of Leconte’s Elements contains a long
list of such names, the greater portion of which have been relegated to
the limbo of synonymy by paleontologists. It is greatly to be desired
that the name “Pteranodon Beds” shall not become established, so long
as there is the least doubt of the validity of the name itself.
KANSAS MOSASAURS.
BY S. W. WILLISTON AND E. C. CASE.