Capitosauroides, Haubold, 1971

Marchetti, Lorenzo, Belvedere, Matteo & Mietto, Paolo, 2017, Lopingian tetrapod footprints from the Venetian Prealps, Italy: New discoveries in a largely incomplete panorama, Acta Palaeontologica Polonica 62 (4), pp. 801-817 : 804

cf. Capitosauroides isp.

Fig. 3 .

Material.—MCV 5, left manus; MCV 6, partial left manus; MCV 7, left pes; MCV 11, right manus; MCV 11/05, right manus; MCV 12, right manus and right pes, possibly of the same step cycle; MGP-PD P3; right pes; all tracks are preserved in convex hyporelief; Ulbe and Cortiana ( Italy) Lopingian.

Description.—Pentadactyl footprints showing medial functionality, relatively long, thick and straight digits with rounded terminations; and short concave palm/sole impressions. Ectaxonic pes, long about 90 mm. Smaller manus, longer than wide, showing relatively thicker digits, and less marked ectaxony. All footprints show very short digit I, digit V is proximally-positioned and usually not preserved.

Remarks.—The ectaxonic pentadactyl footprints with straight thick digits ending in rounded terminations, short concave palm/sole and a very short digit I are typical of Capitosauroides Haubold, 1971 . The pentadactyl manual tracks and the short palm/sole exclude a possible attribution to typical temnospondyl footprints such as Limnopus Marsh, 1894 . The lack of marked impressions of digit I basal pads and the short sole exclude the possible attribution to known reptiliomorph amphibian tracks such as Amphisauropus Haubold, 1970 . Digit proportions, termination and arrangement are distinct from captorhinid tracks such as Hyloidichnus Gilmore, 1927 and Merifontichnus Gand, Garric, Demathieu, and Ellenberger, 2000 . However, the lack of well-preserved digit V and of trackways hampers a definitive assignment, thus we tentatively classify these tracks as cf. Capitosauroides isp.

Capitosauroides was attributed to capitosaurid amphibians ( Haubold 1971) or non-archosauromorph amniotes ( Klein and Lucas 2010). MCV 7 was previously attributed to procolonomorph tracks indet. ( Mietto 1995). We think that these tracks are likely of non-archosauromorph amniotes, and possibly of parareptiles. Capitosauroides shows a proximally-positioned digit V not separated from the digit I–IV group, typical of other possible parareptile tracks ( Erpetopus , Pachypes , Procolophonichnium ). This would be consistent with Mietto (1995), but more studies are needed to confirm the attribution of Capitosauroides to parareptiles.

Figures

Fig. 3. Putative parareptile trace cf. Capitosauroides isp. from Ulbe (Italy), Lopingian.A. MCV 7, left pes impression showing digits I–IV. B. MCV 11/05, right manual impression showing digits I–IV. Convex hyporelief, spacing 0.5 mm. Photo (A1, B1), interpretive drawing (A2, B2), false-color depth map (A3, B3), contour lines (A4, B4). Scale bars 10 mm.