The ventral face is convex lacking ventrolateral or sagittal crests. There are rudimentary articulations for the chevron.
Not taking into account this sagittal crest, the ventral face is convex at midpoint.
The ventral face is generally flat-to-convex and presents a smooth sagittal crest up to CdM, as occurs in the anterior caudal vertebrae.
One particular feature is the presence of a smooth sagittal crest on the ventral face that is just shared by MG 4804 from Salir de Matos (Caldas da Rainha).
Description--Skull short (GLS: 18.8 to 20.5 mm); braincase high, dorsal margin slightly flattened; postorbital region very constricted (INC: 7.5 to 7.9 mm); lambdoidal and sagittal crests greatly developed; supraorbital rims elevated, converging posteriorly; coronoid process and mandibular condyle aligned in parallel with the dentary; apical margins of the upper incisors divergent, I2 located diagonally behind I1; upper canines long with a very conspicuous external cingulum; large P4, triangular in occlusal view; p1 smaller than half the size of p2; molar ectolophs W-shaped; M3 broader than long, half the size of M2.
Description--Skull long (GSL: 19.9 mm) and narrow; lambdoidal and sagittal crests poorly developed; braincase rounded and narrow (BBC: 8.2 mm); mastoid processes poorly developed (MAB: 9.6 mm); rostrum long and narrow; postorbital region constricted, measuring about 3.4 mm; internal margin of the upper internal incisors united from the bases to the apices; two upper premolars, P3 alveolus smaller than P4; M3 alveolus much smaller than the M1 and M2.
Description--Skull long (GLS: 27.7 mm); rostrum narrow, relatively short (LNR 11.6 mm); braincase narrow (BBC: 11.6 mm), poorly elevated; mastoid processes very developed (MAB: 13.9 mm); sagittal crest poorly developed; postorbital region poorly constricted (INC: 6 mm); zygomatic arch narrow (ZYG: 15 mm); incisors 2/2, internal upper incisors larger than the external, different in shape; premolars 2/2, P3 separated from P4 by a short diastema; molars 3/3, ectolophs W-shaped.
Description--Skull large (GLS: 31.2 mm) and robust; rostrum long (LNR: 9.5 mm), robust and heavy; postorbital region very constricted (INC: 8.1 mm); sagittal crest poorly developed; lambdoidal crest well developed; mastoidal processes broad (MAB: 15.7 mm); incisors 1/2, upper incisors in contact at the bases and divergent at the apices, with a well developed internal cingulum; apical margin of the lower incisors bilobed, i2 covered by the cingulum of the canines in occlusal view; canines with external cingulum very developed; premolars 2/2, P3 very small, located at the base of the canine; molars dilambdodont, M3 half the size of the formers, ectoloph in occlusal view form an incomplete "W"; talonid of M3 and m3 reduced.
Vertical migration of the temporalis proceeds, in most adults, to the point where the two masses meet posteriorly and continue anteriorly, initiating the formation of sagittal crests as sites for muscle attachment.
3), and the sagittal crests of older animals often are deviated to one side--see figures in Hall (1981), Jackson (1961), and Stangl et al.
3), and any asymmetry or directional deviation of these scars or of the sagittal crest, were recorded.
The beginnings of a sagittal crest may be evident in advanced cases of muscle development.