Deltapodus, Whyte & Romano, 1994

Pascual, Carlos, Canudo, José Ignacio, Hernández, Nieves, Barco, José Luis & Castanera, Diego, 2012, First record of stegosaur dinosaur tracks in the Lower Cretaceous (Berriasian) of Europe (Oncala group, Soria, Spain), Geodiversitas 34 (2), pp. 297-312 : 301-302

Deltapodus isp. ( Fig. 2 )

DESCRIPTION

The specimen MNS 2009/64 refers to two tracks preserved in convex hyporelief that form a right pes-manus set attributed to a single individual. The size of the tracks is relatively small ( Table 1). The pes track is subpentagonal in shape, elongated anteroposteriorly. It is mesaxonic, with imprints of three short, wide digits with blunt endings at their anterior end. The width of the track is greatest in the anterior part ( Figs 2 ; 3 ). Digit III is projected forwards, whereas II and IV are directed slightly medially and laterally, respectively. The imprint of the heel is large, wide and blunt. The depth of the pes track is variable, reaching a maximum (3 cm) towards the midpoint of its length. In its middle part an irregularity in the surface can be observed, possibly caused by the individual treading on what were probably plant remains.

The manus track is located in an anterior position in relation to pes and slightly medially in relation to its anteroposterior axis. The imprint of manus exhibits an ellipsoid shape with the longer axis running lateromedially and the shorter anteroposteriorly, and it is slightly entaxonic. Its mesodistal width is almost twice its anteroposterior length ( Table 1). It is practically symmetrical and shows on its anterior edge the blunt, scarcely marked imprints of the distal end of digits I to IV. On its posterolateral side it displays a small depression, as a result of which the outline of the track at this point is concave.

The pes-manus set is characterized by the great inequality between the depths of the two tracks, the pes track (3 cm) being greater (pfp / pfm = 1.5) than the manus track (2 cm). The imprints of pes and manus do not touch one another, although they are very close (1.5 cm). The distance between the distal zones of the two tracks is 6.25 cm, and their anteroposterior axes form an angle of 14˚.

Figures

FIG. 2. — Holotype of Deltapodus isp. (MNS 2009/64) from the Early Cretaceous (Berriasian) of Soria (Spain): A, interpretative drawing, made from the bottom of the track, reflecting the true shape of the foot in plantar (B) and lateral (C) views. Scale bar: 2.5 cm.

FIG. 3. — Comparison of Deltapodus isp. (specimen MNS 2009/64) and Deltapodus brodricki Whyte & Romano, 1994 (after Whyte & Romano 1994). The arrows shows the position of digit I. The squared ones are a representation of the surfaces of feet and hands. Not to scale.