Cope, E. D.
[On the structure of the Pythonomorpha].
Proceedings of the Academy of Natural Sciences of Philadelphia, 24:140-141. (meeting of June 11)
© 2002-2011 by Mike Everhart
ePage created 02/03/2002; Last updated 05/21/2011
LEFT: The right front limb of Lestosaurus (= Clidastes), Plate X of Marsh's 1872 paper - "On the structure of the skull and limbs in mosasauroid reptiles, with descriptions of new genera and species."
Wherein E. D. Cope comments on a recent paper by Prof. O. C. Marsh and discusses many of Marsh's discoveries in regard to mosasaurs. Many of the species mentioned by Cope are no longer valid (See Williston, 1898). A complete listing of mosasaur species and their histories can be found on Ben Creisler's webpage. Aside from the comments on mosasaur skeletal anatomy, the article is important to the understanding of the naming of the genus Tylosaurus (Marsh's Rhinosaurus and Cope's Rhamphosaurus).
The type specimen of Tylosaurus proriger (Harvard MCZ 4374) was discovered near Monument Rocks in Logan County, and was obtained by Professor Louis Agassiz during his 1868 visit to western Kansas (Cope, 1869; Williston, 1898; Almy, 1987). It was the first mosasaur to be described from Kansas and was originally named Macrosaurus proriger by Cope.
The following year, Cope (1870, Pl. 12, fig. 22-23) described the Harvard specimen more completely, figured it and, with little explanation, referred it to another European genus (Liodon Owen). Two years later, Marsh (1872a), apparently recognizing significant differences between the American and European mosasaurs, proposed a new genus (Rhinosaurus nose lizard) from a more complete specimen he had collected near the Smoky Hill River. However, that name was preoccupied and Cope (1872) proposed the genus name Rhamphosaurus (this webpage). In a brief note, Marsh (1872b) wrote that "as this name [Rhinosaurus] proves to be preoccupied, it may be replaced with Tylosaurus. The name Rhamphosaurus, since suggested by Prof. Cope, cannot be retained, as it was given to a genus of lizards in 1843 by Fitzinger." Leidy (1873, p. 274) was the first to place Macrosaurus proriger Cope 1869 into Tylosaurus Marsh.
PROCEEDINGS OF THE ACADEMY OF
The President, Dr. RUSCHENBERGER, in the chair.
Twenty-five members present.
Prof. COPE offered some remarks on the discoveries recently made by Prof. Marsh as to the structure and characters of the Pythonomorpha, based especially on material recently obtained by him in Kansas. As the writer had recently passed in review much similar material, he was much interested in Prof. Marsh's conclusions. These, he said, were of importance. In the first place, he had ascertained that what was formerly supposed to be the inner side of the quadrate bone was the outer side, a conclusion Prof. Cope thought entirely consistent with the other known relations of the parts.
Secondly. He had discovered the stapes, and had entirely confirmed the opinion of the speaker, which Prof. Marsh had apparently overlooked. This was stated as follows:1 the quadrate "is characterized by the presence of an oval pit. ... Its use is uncertain, but there is some probability that it received the extremity of an osseous or cartilaginous styloid stapes. A groove on the under side of the suspensorium, would accommodate such a rod, and in a position nearly similar to that which it occupies in many of the Ophidia." It is in precisely this position that Prof. Marsh is so fortunate as to have discovered it.
Thirdly. Prof. Marsh believes that he has found the columnella. I have supposed it to be wanting, from the absence of its usual points of attachment on the parietal and pterygoid bones. It remains to compare the bone found by Prof. Marsh with ali- and orbito-sphenoid and ethmoid ossifications found in many saurians.
Fourthly. Prof. Marsh has observed the parieto-quadrate arch described by the speaker, and makes the interesting observation that it is formed of three elements, the median connecting the parietal with the opisthotic. This piece, he says, is "apparently the squamosal; "as the latter bone completes the zygomatic arch, it cannot occupy a position in the parieto-squamosal, unless it sends a branch in that direction.
Fifthly. He discovers the malar arch, proving it to be incomplete and supported by the postfrontal bone. Prof. Marsh also observes an ossification in the glenoid cavity of the opisthotic, which he regards as the pterotic (of "Huxley," which should be Parker),
1Trans. Amer. Philos. Soc., 1869, p. 180.
NATURAL SCIENCES OF PHILADELPHIA.
an identification which cannot probably be maintained. The connections of the pterotic, where present, are very different. The bone in question is present in Edestosaurus tortor, Cope.
Sixthly. Prof. Marsh completes almost entirely our knowledge of thee anterior limbs. The previous descriptions of these members in Clidastes propython, Cope, Holcodus ictericus, Cope, and other species, had left the number of phalanges and their relative positions, as well as those of the carpal, uncertain; these points are now happily supplied by Prof. Marsh's important researches.
Seventhly. He has done much for the pelvic arch and hind limbs. He was the first to announce the existence of both, and actually described the pelvis of Edestosaurus dispar; the speaker, however, first described the hind limb in Liodon crassartus and L. dyspelor, Cope. Prof. Marsh is in error when he says the "absence of these extremities in the Pythonomorpha was considered satisfactorily established." I had never stated that they were certainly absent, and the last time I wrote observed that this order "possessed an anterior pair only, or with the posterior pair so reduced as to have been insignificant."1 They appear, according to Marsh, to have been relatively small in some of the genera.
In Liodon dyspelor, Cope, the anterior are the smaller. Prof. Marsh lays students under especial obligation for his determinations of the pelvic elements and the excellent figures of all the parts connected with the support of the hind limb. His figure of the fore limb is also highly important, as it "will be difficult soon to duplicate his beautifully complete specimen.
In subsequent pages there are six additional species described, bringing up the number from the Kansas Cretaceous to twenty- three. Two new genera are proposed, viz., Lestosaurus for those previously referred by myself to Holcodus, Gibbes, and Rhinosaurus for species allied or belonging to Liodon. As to the former, it is no doubt a well-marked genus, and I am willing to believe Prof. Marsh's opinion, that it will not include Gibbes' Holcodus acutidens, will turn out to be well founded; but there is, on the other hand, insufficient evidence to show that it is not Platecarpus, Cope. If Liodon curtirostris be referred to it, it will very probably prove to be Platecarpus, as that species presents palatine teeth, much as in P. tympaniticus, and the pleurodont character is not wanting in some of the other species. Rhinosaurus includes such species as Liodon proriger, Cope. As the name has been used two or three times before, it may be altered to Rhamphosaurus, but I have always had doubts that the conic projecting snout would distinguish the species generically from the true Liodon, with which it agrees in dentition. The type of Liodon, L. anceps, ord., is, however, very little known.
1Hayden, Geol. Survey of Wyoming, etc., 1870, p. 385.
Almy, K. J., 1987. Thofs dragon and the letters of Capt. Theophilus Turner, M.D., U.S. Army, Kansas History Magazine, 10(3):170-200.
Cope, E. D., 1869. [Remarks on Holops brevispinus, Ornithotarsus immanis, and Macrosaurus proriger.] Proceedings of the Academy of Natural Sciences of Philadelphia, 11(81):123 (meeting of June 1, 1869)
Cope, E. D. 1870*. Synopsis of the extinct Batrachia and Reptilia of North America. Transactions American Philosophical Society, (n. s.) 14:1-252 + i-viii, 55 figs., 14 pl. (*Note: this is a revision of Cope, 1869, same title, with publication dated listed as August, 1869, published after March, 1870)
Cope, E. D. 1871. On the fossil reptiles and fishes of the Cretaceous rocks of Kansas. Article 6, pp. 385-424 (no figs.) of Part IV, Special Reports, Preliminary Report of the United States Geological Survey of Wyoming and Portions of the Contiguous Territories (F. V. Hayden), 511 p.
Everhart, M. J., 2001. Revisions to the Biostratigraphy of the Mosasauridae (Squamata) in the Smoky Hill Chalk Member of the Niobrara Chalk (Late Cretaceous) of Kansas. Kansas Acad. Sci. Trans 104(1-2):56-75.
Everhart, M. J., 2002. New data on cranial measurements and body length of the mosasaur, Tylosaurus nepaeolicus (Squamata; Mosasauridae), from the Niobrara Formation of western Kansas. Kansas Acad. Sci. Trans. 105(1-2):33-43.
Leidy, J. 1873. Contributions to the extinct vertebrate fauna of the western interior territories. Report, U.S. Geological Survey Territories (Hayden) 1:358 pp., 37 pls.
Marsh, O. C. 1872a. On the structure of the skull and limbs in mosasaurid reptiles, with descriptions of new genera and species. American Journal of Science 3(18):448-464, pl. 10-13.
Marsh, O. C. 1872b. Note on Rhinosaurus. American Journal of Science 4(20):147.
Williston, S. W., 1898. Mosasaurs. The University Geological Survey of Kansas, Part V. 4:81-347, pls. 10-72.