Pachyophiidae

Palci, Alessandro, Hutchinson, Mark N., Caldwell, Michael W., Smith, Krister T. & Lee, Michael S. Y., 2020, The homologies and evolutionary reduction of the pelvis and hindlimbs in snakes, with the first report of ossified pelvic vestiges in an anomalepidid (Liotyphlops beui), Zoological Journal of the Linnean Society 188, pp. 630-652 : 635-636

Pachyophiidae

The pelvis of Eupodophis ( Fig. 2E) is the best known among pachyophiids and consists of an ilium, a pubis and an ischium, all rod-like and not sutured together ( Houssaye et al., 2011). Houssaye et al. (2011) provided a tentative reconstruction of the left pelvic girdle of Eupodophis . The identity and direction (i.e. directed posterodorsally) of the ilium in their reconstruction are confirmed by additional specimens of Eupodophis (MSNM V4014 and MSNM V3661), but we believe the authors are incorrect in their identification of the pubis, which should be the element directed anteroventrally and not the one pointing posteroventrally (compare their fig. 2A, B; the identities of pubis and ischium are switched both in their reconstruction and in the text).

A complete triradiate pelvis, consisting of ilium, ischium and pubis, is also found in Pachyrhachis ( Fig. 2F) and Haasiophis ( Fig. 2D), although the morphology of the individual elements and their contacts are less clear than in Eupodophis . Eupodophis , Pachyrhachis and Haasiophis also have complete, or almost complete, hindlimbs, with long, gracile epipodials and propodials. Haasiophis also still retains at least some metatarsals ( Fig. 2D). It is unclear whether the lack of distal tarsals red. A, Varanus albigularis , lateral view of right pelvis (anterior to the right). B, Tetrapodophis amplectus , right hindlimb as preserved (ventral view) and reconstruction of right pelvis in lateral view. C, Najash rionegrina , right hindlimb as preserved (dorsal view) and reconstruction of right lateral view of right pelvis. D, Haasiophis terrasanctus , reconstruction of left hindlimb (ventral view) and tentative reconstruction of right pelvic girdle in lateral view. E, Eupodophis descouensi , reconstruction of left hindlimb in ventral view and reconstruction of right pelvic girdle in lateral view (based on re-interpretation of reconstruction by Houssaye et al., 2011). F, Pachyrhachis problematicus , right hindlimb in dorsal view and reconstruction of right pelvic girdle in lateral view. G, Wonambi naracoortensis , right pelvic girdle in lateral (left) and medial (right) views. H, Rena (= Leptotyphlops ) humilis , right pelvic girdle and hindlimb in lateral (top) and ventral (bottom) views. I, Epictia (= Leptotyphlops ) albipuncta, right pelvic girdle and hindlimb in lateral view. J, Trilepida (= Leptotyphlops ) dimidiatum , right pelvic girdle and hindlimb in lateral view. K, Typhlops jamaicensis , right pelvic girdle in lateral view. L, Typhlops pusilllus , right pelvic girdle in ventral view (redrawn from List, 1966). M, Indotyphylops (= Rhamphotyphlops ) braminus , left and right pelvis in ventral view, and lateral view of right pelvis. N, Acutotyphlops solomonis , left and right pelvis in ventral view, and lateral view of right pelvis. O, Liotyphlops beui , left and right pelvis in ventral view (not coloured because of uncertain homology). P, Cylindrophis ruffus , right pelvic girdle and hindlimb in lateral (top) and ventral (bottom) views. Q, Anilius scytale , right pelvis and hindlimb in lateral view. R, Candoia carinata , right pelvic girdle and hindlimb in lateral (top) and ventral (bottom) views. S, Tropidophis haetianus , right pelvic girdle and hindlimb in lateral (top) and ventral (bottom) views. T, Ungaliophis continentalis , right pelvic girdle and hindlimb in lateral (top) and ventral (bottom) views. U, Liasis olivaceus , right pelvis and hindlimb in lateral (top) and ventral (bottom) views. V, Antaresia stimsoni , right pelvis and hindlimb in lateral (top) and ventral (bottom) views. W, Morelia viridis , lateral view of right pelvis and hindlimb.

in Pachyrhachis is attributable to a taphonomic artefact or genuine lack of ossification. Two distal tarsals are preserved in Eupodophis ( Fig. 2E).