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Crassithecachelys
Taxonomy
Crassithecachelys was named by Chkhikvadze (2000).
It was assigned to Trionychidae by Chkhikvadze (2000).
It was assigned to Trionychidae by Chkhikvadze (2000).
Synonymy list
| Year | Name and author |
|---|---|
| 2000 | Crassithecachelys Chkhikvadze |
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If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
G. †Crassithecachelys Chkhikvadze 2000
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Diagnosis
| Reference | Diagnosis | |
|---|---|---|
| V. M. Chkhikvadze 2000 | Length of the carapace 20-35 (up to 40) cm. Bones of the carapace and plastron thick and massive. Medial ridge on the nuchal for contact with the first thoracic vertebra is located in the posterior third the plate. Nuchal without marginal glabel (smooth surface). Apophyses on the lateral sides of the nuchal are absent. Suprascapular fontanels, preneural plate and medial keel of the carapace are absent. 8 pairs of costals, 7 neurals (rarely 8), V neural is quadrangular. VI pair of costals wedge-shaped. VII and VIII pairs of costals form caudal margin of the carapace; the VIII costals are considerably reduced, however, the length of the intercostal suture is approximately equal to the length of the free margin of the plate. In old and especially in very old individuals the bony corn (sculptured surface – I. D.) of the carapace is well developed and could completely swallow up (cover) free ribs. Medial apophyses (processes) of the hyoplastra disappear, probably, on the early stages of ontogenesis, whereas medial apophyses on hypoplastra are present in adults and subadults. Ornamentation is absent only on entoplastron and epiplastra. All other elements of the plastron are completely sculptured; bony corn and sculpture is not spread on paired “horns” (? lateral processes – I. D.) of hyo- and hypoplastra. The surface of the lateral lobe of hyoplastron is less than the surface of its medial lobe. Interhyoplastral notch always present (anteriorly) and Interhyoplastral contact – posteriorly. The anterior edge of hyoplastra always has a notch for posterior processes of epiplastron. Axillary notch is absent or weakly developed. Hypoplastra are big, inguinal notch deep. Hypoplastra have wide contact along the midline, but suture never occur between them. Adults and even very old individuals always maintain ento-hyoplastral and hypo-xiphiplastral fontanels. The interxiphiplatral fontanels is slit-shaped, weakly developed or almost absent. Two anterolateral processes of xiphiplastron embrace the hypoplastral thorn, which (?) is located close to the midline. The inguinal margin of the medial lobe of hypoplastron forms almost right angle with the hyo-hypoplastral suture. |
Measurements
No measurements are available
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| Source: f = family, subp = subphylum | |||||
| References: Ernst and Barbour 1989, Carroll 1988 | |||||
Collections
No collection or age range data are available