The gular scutes are triangular, almost as wide as long (Fig.
The members of Promalacoclemmys Reinach, 1900, a genus known in the late Oligocene of Switzerland and the early Miocene of Germany, differ from the Boutersem taxon in several characters, among others: very wide vertebrals in relation to the pleurals, the width from the second to the fourth vertebrals considerably decreasing; first vertebral noticeably wider than the nuchal plate, having a long contact with the posterior margin of the second pair of marginals; relatively long visceral development of the cervical scute; well-developed gular protrusions (Hervet, 2004a).
The abundant material from the early Oligocene of Boutersem allows us to recognize that all character states indicated by Hervet (2004a) as potentially different when Cuvierichelys and Landreatchelys were compared, can be recognized as part of the intraspecific variability of this Belgian taxon: absence of overlap, or more or less overlap of the posterior margin of the fifth vertebral scute on the pygal plate; relative length of the epiplastra; morphology and visceral development of the medial region of the gular lips.
Abbreviations for the scutes (in normal font): Ab, abdominal; An, anal; Fe, femoral; Gu, gular; Hu, humeral; Pc, pectoral.
Batrachemys heliostemma is distinguished from its congeners by its distinct head coloration; diminished size of neck tubercles; lack of horizontal line in the iris; greater parietal roof width; its carapace widest at M7; 4th vertebral scute always wider than long; 11th marginals equal to or wider than 12th; mild upturning of lateral marginals; intergular scute narrower than gulars; greater width of the anterior plastral lobe; its plastral seam formula; and its plastral pattern (see Fig.
raniceps by having a different head pattern and coloration, a broader parietal roof, a more substantial parieto-squamosal arch, ah intergular narrower than its gulars (opposite in B.
Plastron.--The intergular scute bisects 25% of the humeral scutes, and is usually narrower than the gulars at the anterior margin of the plastron.
7b), with which it is sympatric, by the coloration of its head (especially the juvenile banded phase) and plastron; its relatively larger and rounder head; its narrower parietal roof, and narrower parieto-squamosal arch; its shorter barbels; its intergular narrower than gulars; its differences in plastral seam formula; its carapacial flatness, lack of a keel, and presence of a median groove; its 11th marginals being equal to or wider than the 12th; its mildly upturned lateral marginals; and its greatly developed distal antero-medial tibial scale.
7a) by the color of its head (especially the juvenile banded phase) and plastron; its relatively larger, rounder head; its narrower parietal roof width in adults; its usually contiguous neural series lacking a first neural bone; its intergular being narrower than its gulars at the anterior margin of the plastron; its different plastral seam formula; its carapacial flatness; its 12th marginals being equal or wider than 12th marginals; its mild upturning of the lateral marginal scutes; its lack of lateral carapacial narrowing; and its greatly developed antero-medial distal tibial scute.
tuberculata having an intergular scute narrower than its gulars, which is the opposite of all other congeners.
11) Width of intergular scute compared to gulars (at anterior plastron).