Phalangichnus Schmidt, 1959

Ptaszyński, Tadeusz & Niedźwiedzki, Grzegorz, 2004, Late Permian vertebrate tracks from the Tumlin Sandstone, Holy Cross Mountains, Poland, Acta Palaeontologica Polonica 49 (2), pp. 289-320 : 305

Ichnogenus Phalangichnus Schmidt, 1959

Remarks.—Small to medium−sized Rhynchosauroidae representatives. The manual pace width is equal or smaller to pedal pace width. The pedal digit V is relatively small, as long as digit I or II. Pedal digit IV is longer than digit III or may be equal in length to it. Pace angulation ranges from somewhat less than 90° up to 120°, depending on the gait. The stride/pedal length ratio is up to 8. Ichnogenus Phalangichnus shows similarity to the ichnogenus Rhynchosauroides (see Haubold 1971b), from which it differs mainly in the shape of pedal imprint and the length and position of the pedal digit V. Incomplete pedal imprints may show digit tips marked on the same line, being the motivation of the name Phalangichnus ( Fig. 34A, B ), although treated in this paper as “not exactly determinable”. This position of digit tips imprints is highly unusual for Rhynchosauroides tracks.

Phalangichnus was first described by Schmidt (1959) with two new ichnospecies: Phalangichnus alternans and Phalangichnus simulans from the Cornberger Sandstone. Later, Conti et al. (1977) described Phalangichnus perwangeri from the Val Gardena Sandstone. Fichter (1983b) considered Phalangichnus simulans as a synonym of P. alternans . Haubold (1995) and Haubold et al. (1995) considered both Phalangichnus ichnospecies together with Harpagichnus, Akropus diversus (= Anhomoiichnium diversum ) and many other specimens as synonyms of Chelichnus or not determinable specimens ( Haubold and Stapf 1998, see below).

Investigation of Phalangichnus tracks from the Tumlin beds may help to resolve some doubts concerning the possible erroneous interpretation of these trackways. Those described as representing Phalangichnus simulans by Schmidt (1959: figs. 3, 11) and Phalangichnus perwangeri by Conti et al. 1977 (fig. 10, pl. 2: 1, 2) have been left by not one, but at least two animals leaving their trackways along almost the same line overstepping manual imprints by pedal ones. This interpretation explains well the “strange” arrangement of pedal and manual imprints of the Phalangichnus simulans holotype ( Schmidt 1959: figs. 3, 11; Haubold 1984: fig. 68. 1; Haubold 1996: fig. 35A), and remarkable irregularities in the trackway of Phalangichnus perwangeri ( Conti et al. 1977: fig. 10; Haubold 1984: fig. 77). This pattern of trackways left by animals walking along the same line was also observed in specimens from the Tumlin beds ( Figs. 25A , 27B ). Possible erroneous interpretation of the trackways makes the real track features uncertain.

Figures

Fig. 34. A. Muz. PIG OS−220/27: 98–102 five consecutive pedal, partly with accompanying manual imprints preserved in the state characteristic of Phalangichnus. B. Muz. PIG OS−220/73: 76–81 three consecutive pedal and manual imprints preserved in the state characteristic of Phalangichnus. C1. Palmichnus lacertoides ichnosp. nov.; Muz. PIG OS−220/39: 7–12 three consecutive sets of imprints. C2. Phalangichnus gradzinskii ichnosp. nov.; Muz. PIG OS−220/39: 28–33 three consecutive sets of imprints. Scale bars 5 cm.

Fig. 25. Phalangichnus gagoli ichnosp. nov. A. Muz. PIG OS−222/1: 29–41 long, somewhat irregular trackway composed of at least seven sets of imprints, specimens Muz. PIG OS−222/1:42–44 are also visible. B. Muz. PIG OS−222/1:47–56 five consecutive pedal and manual imprints.C. Two trackways, Muz. PIG OS−222/1: 1–6 three consecutive sets of pedal and manual imprints, the second set of imprints is designed as the holotype, Muz. PIG OS−222/1:3, 4 and Muz. PIG OS−222/1: 13–18 three consecutive sets of imprints. D. Muz. PIG OS−222/1: 59–62 two consecutive sets of imprints. Scale bars 5 cm.

Fig. 27. Phalangichnus gagoli ichnosp. nov. A. Muz. PIG OS−222/1: 47–56 five consecutive pedal and manual imprints. B. Muz. PIG OS−222/1: 29–43 eight consecutive sets of imprints; among them imprints (not numbered) of other fragmentary trackways made almost along the same line. C. Muz. PIG OS−222/1: 1–6 three consecutive sets of pedal and manual imprints; the second set of imprints is designed as the holotype. D. Muz. PIG OS−222/1: 13–18 three consecutive sets of imprints. Scale bars 5 cm.