On Pareiasaurus bombidens (Owen), and the significance of its affinities to amphibians, reptiles, and mammals / by H.G. Seeley.

  • Harry Govier Seeley
Date:
1888
Catalogue details

Licence: Public Domain Mark

Credit: On Pareiasaurus bombidens (Owen), and the significance of its affinities to amphibians, reptiles, and mammals / by H.G. Seeley. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    III. Croonian Lecture.—Researches on the Structure, Organization, and Classi- fication of the Fossil Reptilia.—II. On Pareiasaurus bombidens (Owen), and the Significance of its Affinities to Amphibians, Reptiles, and Mammals. By H. G. Seeley, F.R.S., Professor of Geography in King's /CMlpgepBorahw^ Received April 21,—Read May 12, 1887. [Plates 12-21.] The genus Pareiasaurus was instituted by Sir Richard Owen in 1876* for a large number of Reptilian remains from the Karroo Series of strata of South Africa. It was classed with the Dinosauria in a new family named Serratidentia,t and regarded as represented by two species, which were named P. serridens and P. bombidens. Its place among the Dinosauria was held to be established by the teeth, which were compared to those of Iguanodon in their mode of implantation, and to those of Scelidosaurus in their close arrangement and nearly uniform wear, while the margins of the crown are similarly notched or serrate. The cranial characters are stated to concur with the dental characters in supporting the formation of a family in the Dinosaurian order for these fossils. Unfortunately the type-skull of Pareiasaurus serridens is now only known from a plaster cast, and by some small fragments cut from the lower jaw. The immense development of the so-called malar processes, which overlap the lower jaw and suggested the generic name, was regarded as showing a resemblance to the genus Anthodon from South Africa, and in a less degree to Scelidosaurus from the Lias of Charmouth. Regarding the fossil as a vegetable feeder, Sir R. Owen remarked that the homologous descending malar process among Mammals is found only in those types which come nearest to Reptiles in brain structure, such as Kangaroos, Sloths, and Megatheroids. In the cervical vertebrae sub-vertebral wedge-bones are found, which are likened to those which are said to occur in the fore part of the neck of Ichthyosaurs and Plesiosaurs, A notochordal canal penetrates to the centre of the centrum without piercing it, sometimes in a way almost Ichthyosaurian, but sometimes as a slender conical tube extending from the flattened articular face of the centrum. Sir R. Owen * ‘ Descriptive and Illustrated Catalogue of tlie Fossil Reptilia of South Africa,’ 1876. t In the ‘ Quarterly Journal of the Geological Society,’ vol. 32, 1876, p. 45, the family is also named Tretospondylia, and made to include TapinocepJialus and Pareiasaurus.