Mesoplastra are absent. A large, irregular, median fontanelle is present at the junction of hyoplastra and hypoplastra. The posterior plastral lobe tapers strongly in contrast to the squared off end of the anterior lobe. Small articulation facets are present on the xiphiplastra for the pubis. The available shell material of Meiolania platyceps shows a great range of variation.
Most shells have an extensive peripheral overhang but some specimens have almost no overhang.
The shell sulci are usually broad and indistinct but in some specimens they are finely incised with raised edges. The limbs and girdles are completely known in Meiolania platyceps and are represented by both articulated and disarticulated specimens. The shoulder girdle is a stout element with a wide scapular-acromion angle and without a glenoid neck. The coracoid is wide and flat, flaring medially. The pelvis has large but widely separated thyroid fenestrae and a small epipubic process.