TABLE 1. Comparison of some cranial and postcranial characters of three podocnemidids: the new European Eocene genus Eocenochelus (represented by the three species studied here, Eocenochelus lacombianus sp. nov., Eocenochelus eremberti comb. nov. and Eocenochelus farresi sp. nov.), the Malagasy Erymnochelys (represented by the extant species Erymnochelys madagascariensis) and the European Eocene Neochelys (represented by ten species). For more information and detailed comparisons see the text.

  Eocenochelus Erymnochelys Neochelys
Snout Short Prominent Prominent
Premaxillary beak Absent Present Absent
Suborbital space height Greater than the orbits height Less than the orbits height Less than the orbits height
Interorbital space Wider than the orbits length Narrower or as narrow as the orbits length Narrower or as narrow as the orbits length
Cheek emargination Absent. Filled by a ventral expansion of the jugal Small. In large part filled by the jugal or jugal and quadratojugal ventral expansion Largely present between the maxilla and the quadratojugal
Interparietal scute anterior extension Not contacting the frontals Overlapping the frontals Overlapping the frontals
Interparietal anterior concavity Present Absent Present
Mandibular symphysis length About 40% of the lower jaw length About 30% of the lower jaw length About 25% of the lower jaw length
Lower jaw Very robust Relatively robust Slender
Number of neurals 6 to 7 6 6 to 7
Plastral lobes Posterior lobe narrower than the anterior Posterior lobe narrower than the anterior Subequal width of both lobes
Anterior lobe morphology Subrounded Subrounded to subtrapezoidal Subrounded to subtrapezoidal
Intergular length Long, reaching or overlying the entoplastron Short, not reaching the entoplastron Long, reaching or overlying the entoplastron
Medial contact of the gulars Present. Intergular not contacting the humerals Present. Intergular not contacting the humerals Absent. Intergular contacting the humerals, and contacting or not the pectorals

 

TABLE 2. Comparison of shell characters of three representatives of the new European Eocene genus Eocenochelus recognized here: the lower Eocene Eocenochelus lacombianus sp. nov., the middle Eocene Eocenochelus eremberti comb. nov., and the upper Eocene Eocenochelus farresi sp. nov. For more information and detailed comparisons see the text.

  Eo. eremberti Eo. lacombianus Eo. farresi
Number of neurals Al least 7 7 6
Width of the neurals Relatively narrow for their length Relatively wide for their length Relatively narrow for their length
Pubic scar Long and narrow Short and oval Unknown
Posterior branch of the ischiatic scar Poorly-developed Well-developed in the xiphiplastral point but not reaching its extremity Well-developed, reaching the xiphiplastral point extremity
Epiplastral symphysis Relatively long Relatively long Very short
Intergular anterior border Much narrower than that of each gular Almost as wide as that of each gular Almost as wide as that of each gular
Latero-posterior region of the humerals on the hyoplastra Relatively short overlap Relatively short overlap Long
Posterior plastral lobe Relatively wide. Subrounded lateral margins Narrow. Slightly concave lateral margins Narrow. Slightly convex lateral margins
Anal notch Wide and short, the length being about half of the width. Rounded borders Wide and short, the length being about half of the width. Straight borders Deep, being almost as long as wide. Rounded borders