Dimetropus Romer and Price, 1940
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publication ID |
https://doi.org/ 10.5281/zenodo.13510407 |
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persistent identifier |
https://treatment.plazi.org/id/03F387F5-1626-7C25-FFBE-F95B89156276 |
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treatment provided by |
Felipe |
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scientific name |
Dimetropus Romer and Price, 1940 |
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Ichnogenus Dimetropus Romer and Price, 1940 Dimetropus sp.
Figs. 29B View Fig , 30A View Fig , 31D View Fig , 32A, E View Fig , 33D, E View Fig .
Material.—Muz. PIG OS−220/39: 1–6 short trackway with three sets of imprints ( Figs. 29B View Fig , 30A View Fig ). Other specimens, representing? Dimetropus sp. : Muz. PIG OS−220/64 small slab with fragmentary imprint of four digits ( Figs. 32E View Fig , 33E View Fig ); Muz. PIG OS−220/69 slab with scratches of claws ( Figs. 32A View Fig , 33D View Fig ). Not determined specimens possibly representing this ichnogenus include also: Muz. PIG OS−220/70 ( Fig. 31B View Fig ), Muz. PIG OS−220/71 ( Fig. 32B View Fig ) and not collected slab shown in
Fig. 31D View Fig . Description.—The material obtained from Tumlin Gród quarry contains mostly poorly preserved trackways and only fragmentary imprints. A small poorly impressed short trackway Muz. PIG OS−220/39: 1–6 ( Figs. 29B View Fig , 30A View Fig ) shows a stride length of about 280 mm; pedal oblique pace 180 mm and 190 mm; relatively narrow pedal and manual pace width of 80 mm; pace angulation 110°. Pedal imprints, from which specimen Muz. PIG OS−220/39: 3 of the second set is the most completely preserved, 55 mm long and 46 mm wide, diverge from the midline at about –8°. Its digits are 21–29 mm long and narrow, not regularly arranged; exact measurements are impossible. From them, digits I and V are the shortest; digits III and IV seem to be equally long. The divarication of digits I–V attains 50°. All five digits occur in front of a big sole (30 mm long) relatively narrow and asymmetrical in shape. Manual imprints are smaller in size, about 40 mm long and 40 mm wide. Their axes seem to be approximately parallel to axes of pedal imprints. Digits I–IV diverge of about 50°; of them, III and IV are about 26 mm long. Digit V imprint is not preserved.
Remarks.—Specimen Muz. PIG OS−220/39: 1–6 clearly resembles Dimetropus (= Gonfaronipes ) latus Heyler and Montenat, 1980 (see Gand 1987: fig. 58A, B) and specimen described as Chelichnus incurvus Gand et al., 1995 (see Gand et al. 1995: fig. 11, pl. 4.1). The exact comparison of relatively small in size Dimetropus sp. from Tumlin Gród (Muz. PIG OS−220/39: 1–6) with those ichnospecies is now, unfortunately, impossible and needs new, more complete materials.
In Tumlin Gród much larger imprints of? Dimetropus sp. occur, to date only found as indeterminable, poorly and fragmentarily preserved specimens, comparable in the size and shape to those of Dimetropus leisnerianus (Geinitz, 1863) . Specimen Muz. PIG OS−220/64 shows palm part of imprint with four digits showing distinct, big claw marks ( Figs. 32E View Fig , 33E View Fig ). The width of digit group I–IV, which length increases from I to IV, is 70 mm. Digit IV is the longest but slightly narrower than III and II. The divarication of digits I–IV is low, although not exactly determinable. On the slab Muz. PIG OS−220/69 ( Figs. 32A View Fig , 33D View Fig ) only claw scratches made by several big animals are present, accompanying mud cracks. They have been left by large sized trackmakers; with footprints up to 130 mm wide. A similar state of preservation of big footprints Dimetropus leisnerianus was observed by Gand (1987: fig. 50).
Uncollected slabs with poorly preserved, indeterminable, although numerous, imprints were observed in the upper part of the Tumlin Gród quarry ( Fig. 31D View Fig ); Muz. PIG OS−220/70 ( Fig. 31B View Fig ). Specimen Muz. PIG OS−220/71 ( Fig. 32B View Fig ) show presence of similar, big imprints with digit length increasing from I to IV. Its width of the digit group I–IV attains 85 mm. Unfortunately, the shape of whole imprints and trackway features are impossible to determine. The material obtained from Tumlin Gród also contains indeterminable claw scratches or problematic imprints showing the width of digit group I–IV exceeding 150 mm ( Fig. 32C View Fig ), made by very large animals. The length of the largest footprint−like structure exceeds even 200 mm. They testify the possible presence of very large animals leaving footprints comparable in size with the largest ichnospecies of Dimetropus or Pachypes . Such poorly documented and problematic imprints deserve future research.
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