Adocus variolosus Cope 1876
Creators: name: Lambe L., M.
Publisher: name: Zenodo
Year: 1902
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Testudines
Adocidae
Adocus
Adocus variolosus

description: Adocus variolosus, Cope, (sp.) Plate II, figs. 1, 2 and 3. <i>Compsemys</i> ogmius, Cope. 1875. Report on the Geology and <i>Resources of</i> the forty-ninth parallel, appendix B. <i>Compsemys</i> variolosus, Cope. 1876. Proc. Acad. Nat. <i>Sci</i>. Philadel,, <i>vol</i>..xxviii, p. 2.57. <i>Adocus</i> variolosus, Lambe. 1901. Ottawa Naturalist, <i>vol</i>..xv, p. 63, <i>pis</i>. iii, iv, v, and vi. <i>The</i> proportions of the component feloments of the plastron of this <i>species</i> can be seen by referring to figures 4 and 5, where restored outlines are given, based on two fragments of the same shell, which are represented in the <i>figure</i> by the shaded portions. The sutures between the bones are shown by the sinuous lines and the boundaries of the shields by the heavy ones. The dotted lines represent the <i>supposed</i> shape of the end of the posterior lobe, the direction of the sulcus <i>defining</i> the front limit of the femoral shields, and the position of the sulcus that probably crossed the xiphiplastrals, whilst the extent of the hypoplastrals is conjectural. IG, Intergular shield; G, Gular do. <i>JIUM</i>, Humeral do. <i>PEC</i>, Pectoral do. AJJ, Abdominal <i>FEM</i>, Femoral;;; do.; do. <i>AX</i>, Anal do.: <i>EP</i>, Epiplastral hone; <i>SNTP</i>, <i>Entoplastral</i> do.; <i>HYP</i>, Hyoplastral do. HPP, Hypoplastral do. <i>XP</i>, Xiphiplastral do. ;; <i>The</i> plastron is flat except at the sides where it beuds evenly upward, the lobes are short and broad, and the sternal bridge long. The entoplastral is roughly pentagonal and rather broad. The epiplastrals are of not unnsual size and shape, whilst the hyoplastrals are relatively <i>large</i>. A divided intergular shield separates two small gulars, behind which are well developed humeral shields. The pectorals <i>narrow</i> rapidly toward the sides where they and the abdominals meet a series of inframarginals that overlap the peripheral bones. <i>All</i> the sulci are deep and conspicuous except those marking the position of the <i>inframarginals</i>, the anterior boundaries of the <i>gulars</i>, and the division <i> of</i> the intergular. These latter, however,, are sharply and clearly defined. <i>The</i> sutural <i> line</i> between the hypoplastrals and the xiphiplastrals is shown in the smaller of the two fragments. The sculpture consists, when most rugose, of <i>well</i> excavated pits of a rounded hex- <i>agonal</i> outline arranged quincuucially ; the dividing ridges are angular and narrower than the pits are wide, their angularity and height being more pronounced at the junction <i>of</i> every three pits with each other. <i>The</i> formation thus, of three-surfaced, pyrami- dal projections between the excavations, gives to the shell of this turtle its very characteristic and rugose appearance. There are about seven pits in a space of 20 mm. <i>In</i> places a number <i> of pits</i> , as many as half a dozen or more, may coalesce so as to form a continuous groove. The sculpture is most rugose near the edges of both carapace and plastron, elsewhere its <i>roughness</i> is modified and generally toward the centre of the shell the surface is comparatively smooth. On the inner or upper side of the plastron (fig. 5, page 39) the rugose sculpture extends inward for some distance from the free edges of the lobes, more particularly <i>at</i> the extreme anterior end, where also the bone is very much thickened. <i>A</i> decided thickening also occurs in the axillary region. <i>The</i> oval outlines on the xiphiplastrals (P, <i>fig</i> . 5 ) show the position of <i>smooth</i>, slightly raised, <i>flat</i> surfaces that are apparently <i>facets</i> for the articulation of the pubic bones. Large fragments of the carapace show that the cosials are thin and are united to the comparatively thick marginal bones by suture and that the sulci are deep and well defined. <i>In</i> some of the marginal bones the rib-prolongations from the adjacent costals are preserved. <i>The</i> rib-heads of the costals are apparently well developed. <i>In</i> 1901, the anterior half of a plastron (fig. 6, page 41), with the front border of the carapace intact, was obtained below the mouth of Berry creek. <i>This</i> specimen, representing an individual, with a plastron about "840 mm. in length, gives the relative position of the plastron <i>to</i> the carapace anteriorly and also shows an enlargement of the right pectoral shield <i>to</i> the <i>left</i> of the median line of the plastron <i>resulting</i> in a decided diminution in the size of the <i>left</i> pectoral shield. Additional material includes two or three neural bones, some of the bones of the endoskeleton and a few small, thick, conical scutes from the <i>tail</i>. These latter have an upper surface whose sculpture is an <i>exaggeration</i> of that of the most rugose parts of the shell. <i>The</i> types of <i>Compsevxyx</i> og-mius, Cope, from the '' Fort <i>Union</i> group" <i>of</i> Milk river, consisting of two small, poorly preserved fragments of costal bones, show sculpture markings so similar to those characteristic of <i>A</i>. variolosus, that the writer is <i>of</i> the opinion that the two species are identical. On account of the poorness of the type specimens of C. ogmius and to avoid confiision the specific name variolosus is retained. . The foregoing characters indicate a Chelonian that cannot be retained in the genus Compsemys, which is closely allied to Pleurosternon and possesses a mesoplastral element. The presence of two small gular shields separated by a divided* or double intergular shield (in reality two intergulars), and of a series ot inframarginals, the absence of a mesoplastral and of a sutural union of the pelvis with the plastron, together with an abbreviation of the lobes and a decided lengthening of the sternal bridge are characters that suggest such close affinities to the genus Adocus of Cope, that this species has been referred to that genus. [table omitted] Dr. O. P. Hay has informed the writer that in the type specimen there is little, if any, of the carapace represented, that the anterior lobe of the plastron is missing, and that the specimen shows the central portions of the plastron, and the posterior lobe, which latter is broadly rounded. Belly Eiver series, Eed Deer river, 1 89*7, 1898 and 1901. Fragments of the shell had been collected as follows : Professor John Macoun, Mackay creek, 1880 (Belly Eiver series) ; Dr. Gr. M. Dawson, on Old Man river, below Fort McLeod, 1881 (Willow creek subdivision of the Laramie) ; Mr. E. G-. McOonnell, Eed Deer river, 1882 (Belly Eiver series).
description: Published as part of <i>Lambe L. M., 1902, New genera and species from the Belly River Series (mid-Cretaceous), pp. 25-81 in Geological Survey of Canada Contributions to Canadian Palaeontology 3</i> on pages 39-42, DOI: 10.5281/zenodo.3233762