 

 

 

 

 

.. , “ ' .YJOURNAL’W_-i” ﬁ“ ’.,»

ACADEMY. OF NATURAL. SCIENCES

.O'F PHILADELPHIA.

ART. I. — 0n the Fossil genus Basilbsaurus, Harlan, (Zeuglodon, 'Omen,) with a
notice of Specimens from the Eocene Green Sand of South Carolina. By ROBERT a;
W. GIBBES, M. D., of Columbia, South Carolina, Correspondent of the Academy of
Natural Sciences of Philadelphia; of the New York Historical Society, &0.

Ampng the interestihg discoveries of modern Geology, none have excited more
notice than the relics of immense Sa‘uria and Cetacea.

In 1832, Dr. Harlan described a gigantic vertebra, weighing forty—four pounds,
sent to him by Judge Bry from the banks of the VVachita river, which he referred
to a new genus of the class ENALIOSAURI, of Coneybeare, and proposed for it, from its
analogies and gigantic size, the name of Basilosaums.* He subsequently procured.

, from the plantation of Judge Creagh, in Clark county, Alabama, remains of similar
vertebrae, and portions of other bones evidently belonging to the same fossil, which
' he afterwards described more at length, and ﬁgured, in his “ Medical and PhysiCa-l f
Researches.”

In 1835, Professor Agassiz visi'ed England, and observed 1n the collection of the ..
University of Cambridge, a singular tooth, of which Scilla had given a ﬁgure. He , , 1
regarded it as a Mammalian, and published his views of it soon after in Valentin’s
“ Repertorium fiir Anatomie und Phy siologie. ” Viewing it as nearly allied to the
seal family, he proposed for it the name of Phoeodon. ( Pl II, ﬁg. 9. )

In 1840, M. Grateloup published at Bordeaux a “Description d’un fragment de '

' machoire'fossile d’un geure nouveau de reptile (Saurien) voisin de l’Iguanodon.”

*Transactions ofthe American Philosophical Society, Vol. IV., N. S.
. VOL. I. _ . , ° 2

. _, j 954169-

     

6 'DR. R. W. GIBBES ON THE

This fossil was found at Léognan, a few leagues south of Bordeaux, in the calcaire
grossier, or Eocene. The form of the fragment he describes thus:

“ Le museau est alongé, déprinné et va en s’amincissant comme dans le rostre des
crocodiles et de certains lézards. Sa longueur est d’environ dix-huit pouces, et 11’est
pas meme complete. 9t 91* * Ce qui rend cet os fossile fort précieux, c’est la presence de
quatre dents postérieures, implantées dans leurs alvéoles. Le sommet des trois est un
peu endommagé, mais la plus grande est d’une intégrité admirable. Elles sont fortes,
épaisses, subtriangulaires, pointues, comprimées, et aplaties latéralement, un peu
arquées en dedans, fortement dentées en scie, ou plutét crénelées en leurs bords;
celui—ci est tranchant. Les dentelures sont profondes, inégales, plus multipliées du
coté de la téte de l’animal. 11 y en a cinq sur ‘ce bord, a la dent integre,
et deux seulement au bord oppose. Les dentelures présentent, a leur tour, de
ﬁnes denticulations. En résumé, la forme de ces dents rappellent celles des dents
de squale ; et les details des dentelures, rappellent faiblement aussi, ceux de la
structure des dents de l’iguanodon. La hauteur de la dent bien conservée est de
seize lignes, hors de l’alvéole, d’un pouce. Le diamétre, sur ce point, est de six
lignes, tandis que vers la pointe il n’a que deux lignes et demie. La racine est de
forme conique; 'sa longueur doit égaler celui de la profondeur de la cavité alvéolaire,
qui est de neuf a dix lignes, comme je viens .de l’indiquer.” (Pl. 1., ﬁg. 5.)

He doubted whether to refer it to Cetacea or Saurz'a ; and ﬁnally came to the con-
clusion that it constituted a new order of amphibious reptile—a carnivorous marine
animal of the tertiary period—perhaps a connecting link between the Lacertians and
the Sharks, and proposed for it the name of Squalodon. *

In 1839, Dr. Harlan submitted his specimens to Professor Owen, of London, who,
upon a careful examination, expressed the conviction that they were not the bones of
a reptile, but of a great‘cetacean. The microscopic character of the texture of the
teeth, satisfactorily proved them to be mammiferous, and they were compared with
those of the few mammalia whose teeth are devoid of enamel. Professor Owen, with
his paper on the subject, has given ﬁgures of the teeth ; but subsequent specimens
show them to have been imperfect from the absence of the enamel and a portion of
the crownﬁ't

He found the humerus approaching more to the mammalian than to the saurian
types: the vertebrae were strictly mammalian and cetacean ; the teeth being )freely
implanted in distinct sockets with double fangs, had much resemblance, in their inti-
mate structure, to those of the Dugong ; and he was thus induced to place it in the
class and order where it now remains. He says—“ It is to the teeth of the Cachalot
and Dugong, that those of the Basilosaurus offer the nearest resemblance in the par-
ticulars already cited, and I conceive its position in the natural system to have been

*Transactions of the Geological Society of London, Vol. VI.

FOSSIL GENUS BASILOSAURUS. 7

in the cetaceous order, intermediate between the Cachalot and the herbivorous
species.” The peculiar form of a horizontal section of the tooth, suggested the
generic name of ZEUGLODON, (yoke-tooth) (Pl. I., ﬁg. 8,) and the afﬁnity with Cetacea,
the Speciﬁc term cetoz'des. The following extract from Prof. Owen’s paper embodies
his remarks:

“The teeth in their combination of an exaggerated condition of the conjugate
form—which is but indicated in certain teeth of the Dugong, with two distinct fangs,
in their oblique position in the jaw, and the irregular interspaces of their alveoli—
present very striking peculiarities; and when to these dental characters we add the
remarkable and abrupt contraction of the distal end of the humerus, which is never-
theless provided with an articulating surface for a ginglymoid joint, and its remarkably
diminutive size,——-a cetaceous character which is here carried to an extreme; and
when we also consider the dense laminated structure of the ribs, and the third exag-
geration of a cetaceous structure in the extreme elongation of the body of the caudal
vertebrae, we cannot hesitate in pronouncing the colossal Zeuglodon to have been one
of the most extraordinary of the Mammalia, which the revolutions of the globe have
blotted out of the number of existing beings.” The geological position of these
remains was for a long time undetermined; but Mr. Conrad and Mr. Lyell have
satisfactorily referred them to the Eocene period, as well those found in South Caro-
lina and Alabama, as those originally described by Dr. Harlan from the \Vachita
river, in Louisiana.

In 1843, the greater portion of a skeleton of this huge denizen of a former world,
was procured from Clark county, Alabama, and taken to New York by Mr. S. B.
Buckley, who published ’an account of the bones in the American Journal of Science
and Arts ﬁt and a subsequent number of the Journal contains another notice by’Mr.
Buckley of these specimensﬂr They were sent to Albany, and placed by Dr.
Emmons in the saloon of the State geological collection, where I saw them in 1845.
They are now in the possession of Dr. J. C. Warren, of Boston, and have been in
part described by Professor Emmons, in the Quarterly Journal of Agriculture and
Sciencei The ﬁgures given are from perfect teeth, vertebrae and ribs; and Prof.
Emmons, after noticing the drawings of Prof. Owen, expressed his conviCtion that,
after taking all the circumstances into consideration, the two descriptions pertain to
the same animal, and adds—“ Of the bones, besides the vertebrae, we have a femur
or humerus, and the ulna and radius, with a portion of a scapula, a portion of an
enormous pelvis, several ribs, two or three bones corresponding to the wrist, both
extremities of the lower jaw, and the extremity of the upper jaw, and many other
fragments of some importance. The vertebrae extend in a line 65 feet.”

This is the most extensive collection of bones of this animal hitherto found, except-

* Vol. XLIV., for April, 1843. JrVol. IL, for July, 1846, new series. iJuly, 1845, and April, 1846.

8 DR. R. W. GIBBES ON THE

ing those crowded together by Mr. Koch, a German collector, and exhibited by him
as the remains of a single individual, from a single locality, under the erroneous name
of Hydrarchos. It is well known that most if not all of these gigantic bones belong
to the Zeuglodon, the supposed exceptions being some of the caudal vertebrae,
which 'may have pertained to another animal. The identity of the Zeuglodon
and Hydrarchos, was demonstrated to Mr. Koch himself, before he published his
description ; and subsequently Dr. Wyman of Boston conﬁrmed and illustrated this
fact in a masterly manner. Prof. Muller of Berlin, who is now engaged in examining
Mr. Koch’s collection with a view to publication, has come to the same conclusion ;
on which point, however, no one could have a moment’s doubt who has any know-
ledge of the subject.ale

I have in my collection a large vertebra which was presented to me by Mr. Cooper,
of Claiborne, Alabama, and which is the specimen noticed by Mr. Buckley in the
American Journal of Science for July, 1846. It measures eighteen inches in length,
and twelve inches in diameter on the articulating surfaces; and although destitute of
the processes and somewhat broken, it weighs sixty-ﬁve and a half pounds! With
it I received several portions of ribs, corresponding in character with those described
by Dr. Harlan and Prof. Emmons. V

I have lately had an opportunity of examining the cranium of a small Zeuglodon,
(Pl. V.) discovered by Prof. Lewis R. Gibbes, of Charleston, and described by Prof.
Tuomey in the Proceedings of the AcademyqL The characters of this skull aﬁford
additional evidence that Prof. Owen was correct in assigning to the animal a place
among the Cetacea, for it shows a striking afﬁnity to the genus Delphinus. Prof.
Tuomey thinks it belonged to a young animal; but the solidity of the bones and the
tooth, with the apparent full development of enamel, incline me to a contrary belief.
Since I have seen Grateloup’s description of Squalodon, and his ﬁgure, (Pl. I. ﬁg. 5,)
I suspect the two may even prove speciﬁcally identical. The teeth are thinner, the
form of the crown more conical and the serratures more vertical, the crenatures
smaller and shorter, and the neck, at the insertion into the alveolus, more contracted
in the Charleston and Léognan specimens than in the other species now under
consideration.

My supposed discovery of What I called Dorudon, described in the Proceedings of
the Academy for June, 1845, adds another species to this genus. In the noticeI then
published, these remains appeared to me to differ generically from the Z. cetoz'des,

9* Mr. Lyell has published sufﬁcient evidence to show that Mr. Koch’s specimens were obtained in various parts
of Alabama. This is further proved by a letter from Dr. Lister, of Alabama, published in the Proceedings of the
Boston Society of Natural History; and Dr. Dickeson, who has recently made a geological exploration of that state’
conﬁrms the now proverbial fact, that the so-called H ydrarchos was obtained from several different and even distant
localities.

'l‘February, 1847.—Prof. Tuomey’s description is republished in the present volume.

 

 

 

 

FOSSIL GENUS BASILOSAURUS. 9 I

which I had examined in Albany. I founded the distinction on the hollowness of the
teeth and the more elongated, gavial—like form of the beak. The following is the
description, slightly amended, which I then gave of these teeth. (Pl. IV. ﬁgs. 1, 2, 4.)
“ Teeth spear-shaped, the crowns compressed laterally, and in distinct, deep sockets,
with double fangs; the bifurcation commencing a half inch below the enamel, which
extends from the point of the tooth one inch ; enamel smooth, except near the base,
where it is wrinkled vertically ; the serrre longitudinal, diminishing in size from the
apex of the tooth, which is seven-eighths of an inch from the ﬁrst lateral point;
length Of the tooth 3% inches; breadth 2% inches; thickness of the body below the
enamel, a half inch ; the anterior root a cone, compressed laterally; the other pris-
matic, thicker on the posterior side, which is ﬂuted so as to present the appearance of
being partially divided into two fangs : where the fangs are united, the neck is con-
tracted, so that a horizontal section presents the yoke-shape of the Zeuglodon of Owen.
In one Of the teeth the distance from the extremities of the fangs across is 2% inches.”

Besides the serrated molar teeth, which are ﬁgured in a portion Of a lower maxilla,
and which are all similar, I have, two kinds of perfect canine teath of a singlefang
each, one of which was then, and both of whichare now, ﬁgured. One is Curved,
compressed and pointed, resembling very much a ﬁgure given by Faujas de St. Fond*
of a tooth of the Asiatic crocodile or gavial ; though it has no appearanceof a second-
ary tooth, and is contracted at the extremity of the fang, and inserted obliquely in
the socket. It is much compressed laterally and longitudinally, and is hollow,'the
dentine thin, but the enamel developed. A depression on each lateral surface almost
gives it the appearance of being lobed, showing the tendency to the yoke form in the
section. It has also cutting edges on the anterior and posterior compressed sides of
the enamelled crown, and in appearance resembles very much the teeth of Megalo—
sam‘us, though the edges are not serrated, (Pl. IV., ﬁg. 3.) The other canine tooth,
(Pl. IL, ﬁg. 1,) is more straight until within the distance of the enamel from the point,
which is slightly curved. The body below the enamel bulges out, and is not com-
pressed laterally like the former specimen. Casts of both these teeth, and of the
molars, were forwarded to Prof. Owen by my friend Dr. S. G; Morton, who has
kindly favoured me with a letter from that distinguished naturalist, containing his
impressions, on the subject.

“ROYAL COLLEGE OF SURGEONS, Nov. 11, 1845.

“I have been much gratiﬁed by ﬁnding, on my return from a tour in Italy, addi-
tional examples Of your friendly remembrance in the interesting cast of the tooth on
which Dr. Gibbes has founded his genus “Damdon.” It reminds me of the character
of the serrated teeth described by M. Grateloup in the “ Jahrbuch fur Mineralogie,”
1841, p. 830, as those of a fossil carnivorous cetacean for which he proposes the name

* Fossiles de St. Pierre a Maestrecht, Pl. XLIX., A.
3

10 DR. R. W. GIBBES ON THE

Squalodon. I have not, however, seen these teeth, and know them only by Grate-
loup’s brief desert ption.

“With regard to Dorudon, I hat e a stronger suspicion that the large two-fanged,
compressed, serrated tooth which you have transmitted to me, may prove to be an
anterior tooth of ZEUGLODON (Basilosaurus, Harlan.) It would be desirable to deter-
mine accurately the modiﬁcations of form of the teeth in different parts of the jaws
of that very remarkable cetacean, and to this end I trust Mr. Koch’s late discovery
in Alabama may contribute.

“ In the same box was the cast of the tooth of the Mosasaurus, and also two un-
coloured casts of simple teeth. One I take to be the canine of a bear. Were these
found with the serrated teeth of Domdon .7”

Subsequently he says—

“I had written the foregoing before discovering in the pyramid of papers accu-
mulated during my absence, the packet of memoirs which accompanied the casts. I
observe therein that Dr. Gibbes has made the comparison of his Domdon with Zeu-
glodon, and founds a distinction in the form of the jaw. With regard to the hollow-
ness of the teeth of Dorudon, this might perhaps arise from the immaturity of the
individual which yielded the fossils.

“ The ﬁgure subjoined to Dr. Gibbes’s most interesting paper reminded me of the
very old ﬁgure in “ SCILLA, de corporibus marinas; tab. XII. fig. 1, 1747,” of serrated
teeth, which have been the subject of much speculation.* My last views of them
were that they were apparently premolars of the fossil HippopotamusqL Dr. Gibbes’s
discovery may prove them to belong to the very curious family of extinct cetacea of
which BASILOSAURUS is the type, and to which it is most probable that Domdon
belongs.

“The tooth like the canine of a bear” (Pl. II. ﬁg. 1,1) “is not that which Dr. Gibbes
has ﬁgured,” (Pl. IV., ﬁg. 3;) “ the ﬁgured tusk or canine belongs to a different genus
from the tooth I have likened to a bear’s canine, and may probably be from the
lower jaw of Domdon, as Dr. Gibbes supposes.”

The ﬁgured tusk alluded to by Prof. Owen, was subsequently proved to be from
the“ lower ma villa, for I found it inserted in a fragment of that bone. (Pl. 111., ﬁg. 2.)
During an extensive exploration of the bed of green sand at the locality, with the
hope of turning up other portions of the skeleton, fragments of a lower maxilla con-
taining the then unﬁgured tusk were procured, with twelve caudal vertebrae. These
I was disposed to consider as belonging to another species, if not a new genus as sug-
gested by Prof. Owen, but a careful examination of Prof. Warren’s specimens con-
vinces me that I must refer them to Z. cetoz'des.

*I learn from M. Agassiz that the tooth in the University of Cambridge is the original which furnished the ﬁgure
given by Scilla. I have copied one of these teeth from Scilla. (P1. 11., ﬁg. 9.)

TOdontography, p. 564.

:t This tooth was not ﬁgured in my original memoir, but a cast was sent to Prof. Owen.

FOSSIL GENUS BASILOSAURUS. 11

I have two fragments of this maxilla—one ﬁve inches long, containing a canine
tooth with the alveoli of two others, (Pl. 111., ﬁgs. 5 and 6,) and the other of the
opposite side, about three inches. The characters of these specimens I thought were
more Saurian than Cetacean ; there being distinct pits on the outer surface of the jaw,
showing the overlapping of the upper teeth as in Saurians; and the vertebra having
a strong tendency to become convex posteriorly. However, I am now satisﬁed that
they belong to Z. cetoides.

’ Among the fossils of the Eocene period found with these relics, are tympanic bones
and teeth of cetacea resembling Physeter macroceplzalus, and Balwna aﬁm’s, Owen,
as given in his “British Fossil Mammalia.” Several vertebra of a Delphimcs, teeth
of a true crocodile, and others with a compressed lateral cutting edge similar to ﬁgures
given by Prof. Owen in his Odontography, as of extinct Saurians, which Prof. Agassiz
informs me have been ﬁgured by H. Von Meyer, under the name of Madrimosaurus;
a fossil that appears to me to have an analogue in the Crocodilus macrorhyncus of
Harlan.ale

Here also I found teeth of a large Pristis, (Pl. 1., ﬁg. 6 and 7,) differing from
P. acutz'dens, Agassiz.1' The prevalence of Cetacea and Sauria at this period,
together with that of fossils common to the cretaceous and Eocene beds, are inte-
resting facts. These Eocene beds are the lowest in the series, and contain Gryphcea
mutabilis, (Morton,) and Terebmtula Harland, (Morton,) which are also found in the
cretaceous formation ; while Cardita planicosta, (Sowerby,) Scutella Lyellz', (Conrad,)
Pecten membranosus, (Morton,) and other fossils, characterize them as Eocene.

When the Maestricht mom'mur was discovered, it was a long time before naturalists
were able to decide its position in the scale of organized beings. Camper and Van
Marum considered it Cetacean; Hoffman, Drouin, and Faujas de St. Fond insisted
that it was a Crocodile ; but Adrien Camper decided it was neither cetacean, ﬁsh,
nor crocodile, and referred it to a new genus of Saurz'a related to the Monitor, and to
which Coneybeare gave the name of Mosasaurus. Subsequently Cuvier conﬁrmed
the opinion of Camperd: Since that period various new genera have been added to
this remarkable class of fossil reptiles, yet doubts have existed whether some of them
do not possess aﬂinities to the Mammah'a. Cuvier has laid down the following rule,
which is now generally admitted:

“En Zoologie, quand la tete, et surtout les dents et les machoires, sont données,

*Medical and Physical Researches, p. 380 ; and Journal of Academy of Natural Science, Vol. IV., p. 15, 1824.

‘l’This Prism bears some resemblance to P. acutidens, Agassiz, but differs in tapering more gradually from the
root to the point which is more acute. The root is thicker and longer in proportion, and the groove or channel
on the posterior edge is deeper, and extends to the point of the tooth. The body is rather more pyramidal than
conical, as in P. cwutidens. I propose for it the name of Pristis agassizi as a small tribute to the distinguished
author of the great work “ Sur les Poissons Fossiles.”

iCuvier, Ossemens Fossiles, Tome V., p. 314.

12 DR. R. W.» GIBBES ON THE

tout le rested est bien pres de l’étre, du moins pour ce qui regarde les caractéres
essentials ; aussi n’ai je point eu de peine a reconnaitre a classer les vertebres quand
une fois j’ai bien connu la tete.”*

There is, however, an exception in the case of Megalosaurus and Geosaurus. Von
Meyer says of the former, “that notwithstanding the similiarity of the teeth with
those of Geosaums, the structure of the rest of the skeleton differs very considerably.
Among the bones yet found some remind us of the Crocodile, others of the Monitor,
While others have not been sufﬁciently determined. The beak appears to have been
straight and elongated; the Width of the vertebrae at present discovered, exceeds
their length by a third. They are contracted in the middle, as in Streptospondylus ;
both surfaces are plane.”T And he again observes of them, that “the teeth are very
similar, while they have nothing else in common.” Although, in the recent croco-
diles, the vertebrae are convex on one surface and concave on the other, still there
are some fossil species which are plane or concave on both surfaces, and thus re-
semble those of Cetacea.

“In the recent crocodile,” says Dr. Mantell, “the vertebrae are convex posteriorly,
and concave anteriorly; but those from Tilgate, like the vertebra of the crocodile of

. Caen, and of one of the species of Havre, are, with but few exceptions, slightly con-
cave at both extremities”: In Megalosaums both surfaces are slightly concave; in
Iguanodon, they are almost ﬂat on one side and slightly depressed on the other ; in
Geosaums slightly concave; in Streplospondylus “the vertebrae are distinguished by
the very remarkable peculiarity, that their anterior surface is convex, and the hinder
concave ; consequently the reverse of those of the Crocodiles, and formed like the cer-
vical vertebrae of the whole order of terrestrial mammalia.”§ On this peculiarity the
genus Streptospondylus is founded. Cuvier also says :

“ Mais il y a dcs vertébres de grands reptiles, qui ressemblent si fort a celles de
certains dauphins qu’il est facile de s’y tromper ; toujours faudrait—il examiner leur
position avec beaucoup de soin, et voir s’il n’y aurait point, a cet egard, de difference
entre ces os de cétacés et ceux de reptiles.”}|

For several varieties of vertebrae of fossil Saurians differing from the recent species,
I refer to Dr. Mantell’s work on the Fossils of Tilgate Forest. These remarks and
references are necessary in relation to the description of my later specimen, which
possesses characters belonging to the Cetacea and Sauria, though the former pre-
dominate.

In the lower maxilla (Pl. III., ﬁgs. 4 and 6) there are marked differences from the
former, (P1. III., ﬁgs. 1 and 3.) The external surface is convex, the inner hollowed,

’7“ Cuvier, Art. Sauriens, Vol. V., p. 326. »

'lOn the structure of Fossil Saurians, in Charlesworth’s Magazine of Natural History, Vol. 1., p. 341.
IGeology of South East of England, p. 263.

§H. Von Meyer, ut supra, p. 352.

“Letter to G. Mantell, Geology of South East of England, p. 282.

FOSSIL GENUS BASILOSAURUS. ' 13

the two meeting in a sharp angle within and above the longitudinal median line of
the lower surface, which is well exhibited in the sections, (Pl. III., ﬁgs. 3 and 4,)
posterior to the insertion of a canine tooth. The latter specimen, (ﬁg. 4,) upon a
careful comparison with" that of Prof. Warren, I am satisﬁed is identical with it.
From Prof. Emmons’s description I Was disposed to consider them different; but he
was mistaken in describing the anterior portions of the lower maxilla as being united,
and having a groove or sulcus ; whereas they are only united at the terminal extremities
of the rami anteriorly ; the interspace being ﬁlled with the matrix, which requires to be
closely scrutinized to show the fact. I pointed it out to Prof. Wyman when we lately
examined-the specimen together. A little above the longitudinal median line on the
inner face, the inner alveolar process arises like a continuous parapet, of ahalf-inch in
thickness, extending nearly as much above the insertion of the canine tooth (Pl. 111.,
ﬁg 5, a,) which is placed almost perpendicularly in the alveolus. In this respect it is
directly the opposite of the Megalosaurus, where the external edge of the jaw rises almost
an inch above the margin, forming a lateral buttress to support the teeth externally.
Immediately anterior and posterior to this canine, are hollow pits or depressions on
the outer surface of the jaw for the overlapping of the tasks of the upper jaw. In
Prof. Warren’s specimen, this inner thick plate or buttress is distinctly marked, but
Dr. Emmons’s ﬁgure does not represent it. In my ﬁrst specimen there is no such
additional plate, or projecting alveolar process, on the inner side of the maxilla. In
the latter case, the pits, of which two exist in each lateral fragment, certainly show an
approximation in the animal to the Saurz'an rather than to the Cetacean type. Both
are hollow.

“ In all the genera of Crocodilians,” observes Prof. Owen, in his Odontogmpky, “the
teeth of the upper and lower jaws are so placed that their points, instead of meeting,
interlock. In the Crocodiles, (genus Crocodilus,) the ﬁrst tooth in the lower jaw
is received into a notch excavated in the side of the alveolar border of the upper jaw,
and is visible externally when the mOuth is closed.” “In the Gavials, (genus
Gavialis,) the ﬁrst as well as the fourth tooth in the lower jaw, passes into a. groove in
the margin of the upper jaw, when the mouth is closed.” p. 286.

I have not yet seen a perfect upper maxilla, but supposing from the form of the
groOve that a similar tusk existed in the upper jaw, here would be another approach
to the Gavials, (so far as the canines are concerned,) since their teeth are nearly equal in
size and formin both jaws. In the ﬁgures given by Faujas de St. Fond of the Asiatic
and African crocodiles, these pits or depressions in the lower jaw are obvious cha-
racters. '

Of the caudal vertebrae I received twelve, six larger (P1. 11., ﬁgs. 6 and 7) desti-
tute of spinous processes, and six smaller (P1. 11., ﬁgs. 4 and 5) without any pro-
cesses—merely rudimentary notches. The largest of the former is three and a half

inches long, and four inches in the width of the articular surfaces, which are circular
4

1t

14 DR. R. W. GIBBES ON THE

the anterior face is irregularly concave, with a depression in‘ the centre, While the pos-
terior is slightly convex; in the smaller vertebrae (ﬁg. 4) which have no processes, the
concavo-convex character is more marked. Several of the larger vertebrae resemble
the description given by Dr. Mantell* of Cetiosaums; but instead of becoming bi-con—
cave as they approach the caudal extremity, the posterior surface becbmes more
convex. In this respect they resemble the Monitor. All the caudal vertebrae of the
Monitor have the anterior surface concave, and the posterior convex. Pl. II., ﬁg. 8,
represents the caudal vertebrae in position.

The centrum or body of the six larger vertebra, which differ very little in size, is
somewhat contracted in the middle ; and on the sides of the processes is a little de-
pressed: the transverse processes are pyramidal, the base extending the whole length
of the body, next to which, in the centre, is a large oval perforation. This I ﬁnd in
some of the vertebrae in Prof. Warren’s collection. He has no small caudal vertebrae.
On the abdominal surface of the body is a longitudinal depression, which might
almost be called a groove, in the centre of which is a large forarnen, in all the
vertebrae. It is remarked by Professor Owenﬂr that the bodies of the vertebra in
most species of Plesiosaurus, are traversed vertically by two vascular canals, which
lead from the medullary or spinal canal to the inferior surface of the centrum, where
they terminate each by an oriﬁce, and sometimes by two oriﬁces, on each side of the
middle line. These oriﬁces, however, are not a constant character of the genus
Plesiosaurus, neither are they peculiar to this genus, being present in the vertebrae
of the Cetacea as well as those of the Sauria. The medullary cavity is formed by
two lateral processes extending upward and forward, connected by an arched, bony
band. All the apophyses seem anchylosed, for I can ﬁnd no trace of a suture. In
the larger specimens are tubercles for the attachment of chevron bones. ‘

In making a distinction between my two specimens, in addition to the more elon-
gated and tapering form of the jaw, I ’urge the difference in form of the tusks, the
oblique position of the fangs, .and the freedom from the projecting inner plate of the alve-
olus; and I still think the character of hollowness is not entirely to be set aside. Prof.
Wyman is of opinion that the thinness of the dentine and the hollowness are indicative
of the immaturity of the animal; while Prof. Agassiz inclines to the belief that it is not
a young animal, as the enamel is perfectly developed and smooth—not wrinkled as
in young animals. Apart from this character he considers it a different species from
Z. cetoz'des. With these impressions, I propose for it the speciﬁc name of serratus.

The‘question now arises whether Dr. Harlan’s original name of BASILOSAURUS should
or should not be restored to the remarkable remains now under consideration. That
it is objectionable in a critically zoological point of View, we grant; but it is not
more so than many other names that are admitted in the systems, among which we

*Medals of Creation, p. 727. “Report on British Reptiles.

fa

 

FOSSIL GENUS BASILOSAURUS. ' 15

may, by way of example, refer to that of Serums, which Cuvier has applied to a
genus of Fishes. In the order of priority, Prof. Agassiz’s Phocodon supercedes Zeu-
glodon, which latter designation only expresses a character of the teeth, which is
equally present in some of the Dugongs and Seals. Of the several names—Basile-
saurus, Phocodon, Squalodon, Zeuglodon and Dorudon, which have been successively
applied to these fossil remains, I respectfully suggest the propriety of restoring the
original appellative of the discoverer; and in so doing I further propose, in the
present state of our knowledge, to recognize three species of this extraordinary genus,

thus 2
BASILOSAURUS. Harlan.

1. B. cetoides. Owen.
2. B. serratus. G'ibbes.
3. B. squalodon. Grateloup.

 

REFERENCE TO THE PLATES.
PLATE I.

Figs. 1 and 2. Anterior extremity of lower maxilla, (reduced) Dr. Emmons’s collection.
“ 3. Molar tooth, (natural size.) Dr. Emmons’s collection.
“ 4. Large vertebra, (reduced) Dr. Emmons’s collection. ..
“ 5. Fragment of upper maxilla, from Léognan in the Gironde. Squalodon of M. Grateloup.
“ 6 and 7. Pristis Agassii, (nobis.) .
“ 8. Section of molar tooth of Basilosaurus cetoides, from Prof. Owen’s Odontography.
PLATE II.
Two vieWS of canine teeth of B. cetoides. The author’s collection.
. Section of canine tooth of B. serratus. The author’s collection.
. Section of canine tooth of B. cetoides. The author’s collection.
. Small caudal vertebra of B. cetoides, (natural size.) The author’s collection.
. Small caudal vertebra, posterior articular surface, (natural size.)
“ 6 and 7. Large caudal vertebrae of B. cetoides, (one-fourth natural size.) The author’s collection.
“ 8. Twelve caudal vertebrae reduced, and in relative position.
“ 9. Tooth of the Basilosaurus of Malta, copied from Scilla. Phocodon of Prof. Agassiz.

PLATE III.

. Fragment of lower maxilla of B. serratus. The author’s collection. a

. Fragment of lower maxilla of B. cetoides. The author’s collection.

. Section of ﬁg. 1. '

. Section of ﬁg. 2.

. Upper surface of ﬁg. 6.

. Anterior fragment of lower maxilla of B. cetoides. The author’s collection.
PLATE IV.

. Fragment of lower maxilla and teeth of B. serratus.

. Edge View of molar tooth of B. serratus, (natural size.)

. Lateral View of the same tooth.

. Two views of a canine tooth of B. serratus.

, PLATE V.
Cranium of Basilosaurus, found in the Eocene near Charleston, South Carolina.

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[16]

ART. II.——N0tice 0f the Discovery of a Cranium of the Zeuglodon, (Basilosaurusyle
By M. TUOMEY, State Geologist of South Carolina; Corresponding Member of
the Academy of Natural Sciences of Philadelphia.

Almost every day adds something to our knowledge of those remarkable forms
which, in the revolutions, of time have passed out of existence. In 1832, Dr. Harlan
described and ﬁgured in the American Philosophical Transactions some fossil bones
from Alabama, consisting of portions of the upper and lower maxillee of an animal
to which he gave the name of Basilosaurus, from an impression that they belonged
to a gigantic Saurian. An examination of the teeth, however, satisﬁed Prof. Owen
that these remains pertained to a Cetacean, to which he has given the name Zeuglodon.

The ﬁrst description of an entire tooth of this animal, was given by Mr. Buckley,
in a concise account of the discovery of a considerable portion of the skeleton, pub-
lished in the American Journal of Science in 1843. In 1845, Dr. R. W. Gibbes, of

South Carolina, published in the Proceedings of the Academy of Natural Sciences
of Philadelphia, accurate ﬁgures of similar teeth with fragments of the lower maxilla.
- The teeth being hollow, and in his opinion presenting other important differences, he
constituted for them a new genus, Domdon.

The' Hydrarchos, I believe, has passed away without advancing our knowledge
upon this interesting subject, excepting perhaps that Prof. Wyman discovered in the
extremity of the ribs some cetacean characters.

The next important development consisted in the publication, by Prof. Emmons, in
the American Quarterly Journal of Agriculture, of beautiful ﬁgures of the teeth, the
anterior portion of the lower maxilla, part of the ramus having the coronoid process
and condyle almost perfect, together with cervical and caudal vertebrae, and a rib.
But up to the present time, no notice has appeared of the discovery of any consider—
able portion of the cranium proper—for the mutilated head of the so-called Hydrm‘;
ch03 can scarcely be considered an exception.

Early in January I was presented by F. S. Holmes, Esq., with a portion of the left
upper maxilla, containing one tooth and the alveoli of several others, which he dis-
covered in the Eocene beds of Ashley river, about ten miles from Charleston. Soon
after, Prof. Lewis R. Gibbes, of the College of Charleston, visited the same locality,
and had the good fortune to ﬁnd the rest of the scull, much fractured, but so care-
fully were the fragments collected, that with a little patience we were enabled to
restore them to their proper places. It isthen altogether to these gentlemen that we
owe a knowledge of this valuable relic.

* Proceedings cf the Academy of Natural Sciences, February, 1847.

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MR. TUOMEY ON THE ZEUGLODON. 17

Description. Occipital bone somewhat semicircular, transversely ﬂat or slightly
concave, central portion thin ; a crest-like ridge surrounds the superior portion termi-
nating in the suture with the temporal bone. Condyles two, articulating surfaces
lunate, and almost enclosing the foramen magnum. Foramen magnum oval; trans—
verse diameter 1% inches, vertical diameter 1 inch; transverse processes thick,
spreading, making the breadth of the base of the cranium equal to its diameter across '
the zygomatic processes; jugular foramen ,1, inch in diameter; temporal bones small,

. mastoid portion thick and strong but not prominent; articulating cavities for con-
dyles of lower maxilla large, forming about 30° of a circle, inclining inwards and
backwards; maxillae thick and strong, vertical section triangular ; a cavity for nerves
and vessels runs within at the points of the roots of the teeth ; alveolar process thick;

‘ palatal bone strong, anteriorly emarginate and horizontal, posteriorly descending

below the alveolar process.

Frontal bone and anterior portion of maxillae wanting; walls of the nasal canal
smooth; sutures squamous; in the left maxilla one tooth. remains, which is solid, spear-
shaped, edges coarsely serrate, exterior side ﬂattened, interior side convex, agreeing
in this respect with the position of the teeth in the shark ; roots double, nearly paral-
lel, and inserted obliquely backwards ; in the right maxilla are the alveolae for eight
teeth with double roots. In the solidity of the teeth and~slight divergency of the
roots, this specimen agrees with the ﬁgures of Dr. Harlan and Prof. Emmons.

This fossil is particularly interesting, as it removes every doubt, if any remain,.of
the true character of the animal to which it belonged. The double occipital condyle
shows it to have been a mammal, while the squamous sutures and a symmetrical
form refer it to the Cetaceze. 4

Dimensions. Length 14% in.; greatest breadth 7% in.; height 5% in. ; length of
enameled portion of tooth % in.; breadth 3 in. It was evidently a young individual.
(Pl. V., ﬁg. 1 and 2.)

Geological position. The teeth described by Dr. Gibbes were found in the oldest of
the calcareous beds of the Eocene of South Carolina, which contain Carditaplanicosta,
(Sowerby,) and other well known Eocene fossils, together with ‘Gryphcca mutabz'lz's,
(Morton,) and’TerebratuZa harlani, (Morton,) which are also common to the creta-
ceous formation. The fossil just described was found in upper beds of the Eocene ;
so that the Zeuglodon must have existed through the whole of the Eocene period ;' a.
period which, in South Carolina, was at‘ least sufﬁciently long for the deposition of
three hundred feet of calcareous and sedimentary matter; a fact ascertained by
boring at Charleston. -

['18]

ART. III. —Obse7'vations on certain Fossil Bones from the collection of the Academy of
Natural Sciences of Philadelphia. '36 By RICHARD OWEN, Esq, F. R. S., Professor
‘ of Comparative Anatomy 1n the Royal College of Surgeons, London, &.c., &c.T

Genus Bos.

No. 1. Distalhalf of right humerus: it is about one-sixth less than the same part
in 305 piimigenius, and more resembles that of the Aurochs: it belongs, probably, to_
a speCies of Bison. '

No. 2. The left tibia of the same species.

Genus EQUUS.
_ No. 3. Fragments of a lower molar tooth of the size of the Eguus cahallas; but the
speciﬁc character not determinable.

Genus MASTODON.

No. 4. A7 portion of tusk, labelled Hippopotamus, but satisfactorily known to have
belonged to a ProboScidian Pachyderm by the decussating curved lines intercepting
lozenge-shaped spaces, at the transverse fractures of the ivory at the two ends. This
structure is shown in British Fossil Mammalia, p. 291, ﬁg. 101, 0. Transverse frac-
tures of the tusks of Hippopotamus show fine concentric lines, as ﬁgured in British
Fossil Mammalia, p. 402, ﬁg. 160.

From the size, shape and slight degree of curvature of the Georgian fossil, it may
probably have belonged to the left side, lower 3aw, of the Mastodon giganteas.

Genus HARLANUS Plate VI.,

No. 5. The middle part of the right ramus of the lower Jaw of alarge Paohyderm,with
the last three (or true) molars, part of the premolar next in advance, and part of the
socket of another premolar. The crowns of all these teeth appear to have been worn
down by mastication to their base ; they present the proportions, and the last molar,
in a cast transmitted to me by my lamented friend Dr. Harlan, appears to retain the
anterior of the two large transverse ridges, which characterize the teeth of the genus
Lophiodon, Cuv. : it likewise possesses the large posterior lobe or talon, which dis—

* Proceedings of the Academy of Natural Sciences, August, 1846.

'l'The organic remains which form the subject of this paper are a part of a series collected by James Hamilton
Couper, Esq., during the excavation of the Brunswick Canal, near Darien, in Georgia. Prof. Owen, having
expressed a wish to examine these fossils, they were transmitted to him through Mr. Charles Lyell, by authority
of the Academy, and the following highly interesting memoir was promptly returned. Besides the reference by
Professor Owen to Dr. Harlan’s original paper in the American Journal of Science, some valuable remarks by Mr.
Couper himself, will be found in Vol. I._ of the Proceedings of this Academy, page 216.

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PROF. OWEN ON CERTAIN FOSSIL BONES. l9

tinguishes this tooth in the Lophiodon from that of the Tapir. The teeth of the fossil
from Georgia a little exceed in size those of the Lophiodon Isselanas (Grand Lophiodon
d’Issel, Cuvier, ‘ Ossemens Fossiles,’ ed. 1822, tom. 2, pt. 1, p. 184, pl. 3, ﬁg. 3,) the
antero-posterior diameter of the last molar in that species being one inch and eight
lines, and in the present fossil one inch ten lines. But the depth of the jaw beloW
the middle of the last molar in the present fossil is three inches ; whilst’that in the
Loplziodun Isselanus in the ﬁgure cited, is scarcely two inches; and Cuvier expressly
states (p. 186) that it surpasses in depth the corresponding part of the jaw of the
Lophiodon medias (pl. 3, ﬁg. 1,) which has molar teeth of the same size as in the
Lophiodon Isselanus.

The present fossil has been described and ﬁgured in “ Silliman’s American Journal
of Science,” vol. 43, 1842, pl. 3, ﬁg. 1, under the name of Sas Americana; Dr. Harlan
conceiving that from its general appearance and number of the teeth this fragment
bore a close analogy with the same part in the Sas babirussa, Buff, acknowledging,
however, that the Babyroussa “ was a much smaller animal.” Besides the difference
of size, the last molar in the fossil has the anterior transverse ridge proportionally
larger, and the posterior lobe proportionally smaller than in the Babyroussa, resem-
bling the Lophiodon in the points in which it thus differs from the species of Sas cited.
The form of the fossil jaw differs at the part supporting the last molar from that in
the Babyroussa, where the socket of the last molar overhangs the inner surface of the
ramus, whilst in the fossil the inner surface of the ramus beneath the last molar
describes a gentle convexity from the tooth to the lower margin of the ramus The
outer part of the ramus of the jaw of the Babyroussa begins to expand below the
fourth and ﬁfth molars, counting forwards from the last, to form the socket of the
large tusk ; but the fossil jaw does not offer the least indication of an enlargement
for that purpose; and the fractured anterior end, as displayed in the cast, is very
different in shape from the correSponding part of the jaw in the Babyroussa, and
shows merely the wide dental canal, and no socket for the tusk which would be here
situated in the Babyroussa or \Vild Boar.

The nearest approximation which I could make from a studv of a cast of the fossil
in question to any known existing or extinct animal, was to the great tapiroid Pachy-
derms; but I added in my description of this cast in the “ Catalogue of Fossil Mam-
malia and Birds in the College of Surgeons,” 4to., 1845, p. 198, “that ulterior dis—
coveries, may, indeed, show that the Lophiodont dentition was combined with other
characters in the American fossil, necessitating a generic distinction, and it is well to
remember that the dentition of the Mt‘tcranchenia, of South America, a three-toed
Pachyderm with an astragalus almost identical with that of the Lophiodon, and of a
size which agrees with the jaw of the fossil Sas Americana of Harlan, has yet to be

discovered.”
The original of the cast shows the course of the enamel on the outer side of the

20 PROF. OWEN ON CERTAIN FOSSIL BONES.

penultimate molar ; it there deﬁnes an anterior lobe of the crown about the one-third
the antero—posterior extent of the crown, by a close, straight fold of enamel penetrating
inwards about 2% lines.

The anterior lobe or transverse ridge of the corresponding tooth of a Lophiodon
might, perhaps, present a similar appearance, if worn down to the base of the croWn.

But in the present fossil, the enamel proceeds to deﬁne a middle lobe on the outer
side of the crown, shorter than the foregoing, beyond which the enamel and dentine
are worn obliquely away to the base of the posterior fang; the indication of the
middle external lobe or festoon of enamel is, however, decisive against its generic
relationship with Lophz'odon.

This indication of the arrangement of the enamel, slight as it is, reminds one of
i that in the lower molars of the Toxodon,* and another feature of resemblance is the
apparent interruption of the enamel at the anterior part of the molar in the fossil. If
the presence of two distinct fangs in the Georgian Fossil were adduced as dis-
tinguishing it from the Toxodon, it might he replied that perhaps the long curved
rootless molars in that animal at the last period of age might, as in the Horse, acquire
root _

But the trilobed character is on the outside of the molar in question, and on the
inside of those of the Toxodon; in which also the middle lobe only has a coat of
enamel, not the anterior or posterior cf the inner lobes: there is no doubt, therefore,
that the Georgian Pachyderm is as generically distinct from Toxoclon, as it is from
Lophz'odon; and it would seem to have diminished the interval which divides the
strange Gliriform Pachyderm of South America, from the more normal Tapiroid
forms of Pachyderms which are found fossil in the old world.

As naturalists have accepted the latinized Indian word Tapirus as the generic
name of the existing American Pachyderm, which makes the nearest approach to the
present remarkable fossil, they will probably sanction the application to the genus
and species which it represents, of the name Harlcmus Americanus ,‘T in honour of the
indefatigable and accomplished naturalist by whom the fossil was ﬁrst made known
to science.

A Royal College of Surgeons, London, July 8th, 1846.

+ Fossil Mammalia of the Beagle, pl. 5, ﬁg. 2.
TThe annexed drawing of this fossil was made in London under the supervision of Prof. Owen.

 

 

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