Madtsoiidae, Hoffstetter, 1961

Folie, Annelise & Codrea, Vlad, 2005, New lissamphibians and squamates from the Maastrichtian of Haţeg Basin, Romania, Acta Palaeontologica Polonica 50 (1), pp. 57-71 : 68

Madtsoiidae indet.

Fig. 5G.

Material.—PSMUBB V 407 (one incomplete vertebra).

Description.—This vertebra is 5.5 mm long, 5 mm wide, 4 mm high ( Fig. 5G). It is deformed, as the cotyle is not aligned with the rest of the vertebra. Anteriorly, a wide and slender zygosphene is present and there is no prezygapophysial process. Posteriorly, the postzygapophysis and the zygantrum are lost. The condyle is dorso−ventrally compressed. Laterally, only the right part of the bone is preserved. The paradiapophysis is very expanded and rather low on the bone. The diapophysis is wider than the parapophysis. There is no parapophysial process. Dorsally, the neural spine is lost. The prezygapophysial articular facets are wide, nearly horizontal, not tilted upward with an antero−lateral great axis. Ventrally, there is no hypapophysis but a wide and poorly defined haemal keel. The paracotylar, subcentral and lateral foramina are present but not well visible.

Discussion.—The absence of prezygapophysial process is a primitive character present in rare Ophidia such as the Madtsoiidae ( Sigé et al. 1997) . But it is not always easy to see whether this element is present or not ( Rage 1973). This family is mainly defined as follows: presence of parazygantral and paracotylar foramina and absence of prezygapophysial process (e.g., Rage 1996). The two latter characters can be observed in the Pui Islaz sample.

Sigé et al. (1997) attributed two fragmentary vertebrae from the Campanian of Champ−Garimond ( France) to the Madtsoiidae because of the presence of a parazygantral foramen and the absence of prezygapophysial process. Only the latter character is shared with the specimen from Pui Islaz. A more detailed comparison is therefore impossible.

Rage (1996) described two madtsoiid snakes from the late Campanian of Laño ( Spain). In the first, Madtsoia , the haemal keel is less marked off from the centrum, like in the specimen from Pui Islaz, but the zygosphene is thicker and the centrum is shorter. The second form, Herensugea , shares the following characters with the vertebra from Pui Islaz: a wide and thin zygosphene; nearly horizontal, oval and anterolaterally oriented prezygapophyseal facets, and a wide and not markedly salient haemal keel. But the paradiapophyses of Herensugea are not as large as in PSMUBB V 407 and the prezygapophysial facets are wider and shorter. According to the same author, the small size of PSMUBB V 407 and the wide and thin zygosphene are characteristic for small Madtsoiidae .