Phalangichnus gradzinskii, Ptaszyński & Niedźwiedzki, 2004

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 : 306-307

publication ID	https://doi.org/ 10.5281/zenodo.13510407
persistent identifier	https://treatment.plazi.org/id/03F387F5-1620-7C2C-FFBE-F88C8EA566A3
treatment provided by	Felipe
scientific name	Phalangichnus gradzinskii
status

Treatment

Phalangichnus gradzinskii ichnosp. nov.

Figs. 22A–C View Fig , 23A–C View Fig , 24A–D View Fig , 34C View Fig 2 View Fig .

Holotype: Set of right pedal and manual imprints, Muz. PIG OS−220/30B: 5, 6 ( Figs. 23C View Fig , 24B View Fig 1 View Fig ).

Type locality: Tumlin Gród quarry, 11 km NW of Kielce, Holy Cross Mts., Poland.

Type horizon: Tumlin beds, Lower Buntsandstein, uppermost Permian.

Derivation of the name: In honour of Ryszard Gradziński, who studied the Tumlin beds sedimentary environment and discovered vertebrate tracks there for the first time.

Material.—Muz. PIG OS−220/30A: 1–12 six consecutive sets of pedal and manual imprints, Muz. PIG OS−220/30B: 1–6 natural casts of the same trackway as Muz. PIG OS−220/30A: 1–12, showing the consecutive sixth, seventh (partly preserved) and eighth set of imprints, from which the eighth one, right pedal and manual imprints, Muz. PIG OS−220/30B: 5, 6 are designed as the holotype ( Figs. 22A–C View Fig , 23C View Fig , 24A, B View Fig ); Muz. PIG OS−220/27: 92–97 three consecutive sets of imprints, Muz. PIG OS−220/27: 86–91 three consecutive sets of imprints. Isolated imprints: Muz. PIG OS−220/38: 1 left pedal imprint ( Figs. 23B View Fig , 24C View Fig ); Muz. PIG OS−220/53: 1 left pedal imprint ( Figs. 23A View Fig , 24D View Fig ); Muz. PIG OS−220/39: 28–33 three consecutive sets of imprints ( Fig. 34C View Fig 2 View Fig ).

Diagnosis.—Medium−sized Phalangichnus having manual axes inclined to the midline at +13.5°; pedal imprints slightly diverging out from the midline at –4°. Pedal pace angulation varies from somewhat less than 90° up to 115°. The manual pace width is only a slightly less than the pedal pace width.

Description.—Trackways. The manual pace width is somewhat smaller than the pedal one, which connects with similar pace angulation in the trackway containing the holotype, Muz. PIG OS−220/30A: 1–12 and Muz. PIG OS−220/30B: 1–6 ( Figs. 22A–C View Fig , 23C View Fig , 24A, B View Fig ) close to 90°. Pedal imprints diverge from the midline at about –4°, while manual axes are inclined to the midline at +13.5° on average. The stride/pedal length ratio is only 4.6. The average manual width of pace, 104 mm is very close to the pedal one, 122 mm. The trackway with the holotype is somewhat irregular. In the more regular part of the trackway, the average manual pace angulation, 88°, somewhat exceeds the pedal one, 85°. In other trackways enclosed to the material, Muz. PIG OS−220/27: 92–97 and Muz. PIG OS−220/27: 86–91 the pedal pace angulation exceeds 90°, ranging from 97 to 115°. The pedal pace width exceeds 1.3–1.6 times the manual one. Pedal axes are almost parallel to the midline attaining the average angle of –4°. The manual inclination to the midline is +13.5°. Manual imprints are situated more or less before pedal ones, but have never been observed overstepped by them. In the trackway containing the holotype and also the trackway Muz. PIG OS−220/39: 28–33 ( Fig. 34C View Fig 2 View Fig ), the tail mark is present, although poorly visible.

Pes.— The pedal length in the type trackway, 50 mm, distinctly exceeds its width, 38 mm. The group of digits I– IV is almost as long as it is wide, 37 and 38 mm, respectively. The length of digits I– IV equals average values 24, 28, 30, and 31 mm. All those digits have distinct claw marks. The digit V is relatively short, long as like as the II, situated backward from the digit group I– IV. Pedal digits II / IV, l/ IV and I/ V diverge of. 25.5, 37, and 54°, respectively .

Manus.—Manual imprints are 33 mm long and 31 mm wide. From the digit group I–IV, of which length somewhat exceeds the width (33 and 31 mm) first four digits increase in length from I to IV: 16, 19, 24.5, and 25.5 mm on average. The digit V length is comparable with that of II, 20.5 mm. Digits II/IV, I/IV and I/V diverge of 36.5, 48, and 88.5°, respectively.

Discussion.—The small number of fully preserved trackways under description is caused by the similarity of mostly incompletely preserved imprints to other Rhynchosauroidae ichnospecies present in the Tumlin Sandstone. Many tracks found at Tumlin Gród and Sosnowica Hill quarries may represent this ichnospecies, but appear usually as only digit tips imprints, and therefore are hardly distinguishable from other Rhynchosauroidae representatives ( Fig. 34A, B View Fig ). Their main characteristic features are close pedal and manual values for pace width and low pace angulation angle. Also characteristic is the arrangement of digits I–IV tip imprints along a straight line, a feature stated by Schmidt (1959) as characteristic of the ichnogenus, not found by authors in Rhynchosauroides imprints. The characteristic arrangement of digit tips may result from dragging on the substrate causing elongation of imprints of the first two digits ( Figs. 22B, C View Fig , 23B View Fig , 24A View Fig 2 View Fig ). Trackways with such incomplete imprints ( Figs. 34A, B View Fig ) have not been included in this ichnospecies but are treated in this paper as determinable only to the ichnogeneric level. Phalangichnus gradzinskii ichnosp. nov. shows similarity to Phalangichnus alternans Schmidt, 1959 , having a higher stride/pedal length ratio and a distinct, big manual digit V imprint, being much more similar to Rhynchosauroides manual imprints (see Schmidt 1959: fig. 10). Pedal imprints of Phalangichnus alternans , although similar in size, are narrower and distinctly directed outward from the midline. The exact comparison of those two similar ichnospecies is difficult because of incomplete preservation of Phalangichnus alternans specimens, this being the reason for doubts of the authors of revision works (see below). From Rhynchosauroides kuletae ichnosp. nov., Phalangichnus gradzinskii ichnosp. nov. differs clearly in size and arrangement of digit V (if visible), and much more close values of the pedal and manual width of pace. The overstepping of manual imprints by pedal ones have not been observed. In fragmentary or poor trackways both ichnospecies are not always easy distinguishable.