A distinctive crouching theropod trace from the Lower Jurassic of Poland

Geo log i cal Quar terly, 2009, 53 (4): 471–476

A dis tinc tive crouch ing theropod trace from the Lower Ju ras sic of Po land

Gerard D. GIERLIŃSKI, Mar tin G. LOCKLEY and Grzegorz NIEDZWIEDZKI

Gierliński G. D., Lockley M. G. and Niedźwiedzki G. (2009) — A dis tinc tive crouch ing theropod trace from the Lower Ju ras sic of Po - land. Geol. Quart., 53 (4): 471–476. Warszawa.

A well-pre served, es sen tially com plete and dis tinc tive trace fos sil of a crouch ing, me dium-sized theropod di no saur is re ported from the north ern slope of the Holy Cross Moun tains, Po land. Crouch ing theropod traces are rare, and cur rently known from only six spec i mens from the Ju ras sic of North Amer ica and Asia. Thus, this new spec i men adds a sev enth spec i men to the di no saur track re cord. The spec i - men was found in the Early Ju ras sic (Late Pliensbachian) sand stones mined in the Szydłówek quarry, in the vi cin ity of Szydłowiec.

Gerard D. Gierliński, Pol ish Geo log i cal In sti tute–Na tional Re search In sti tute, Rakowiecka 4, PL-00-975 Warszawa, Po land; JuraPark, ul. Sandomierska 4, PL-27-400 Ostrowiec Świętokrzyski, Po land; e-mail: gierlinski@ya hoo.com; Mar tin G. Lockley, De part ment of Ge ol ogy, Uni ver sity of Col o rado at Den ver, P.O. Box 173364, Den ver, CO80217-3364, USA; Grzegorz Niedźwiedzki, De part ment of Zo ol ogy, Fac ulty of Bi ol ogy, Uni ver sity of War saw, S. Banacha 2, PL-02-097 Warszawa, Po land (re ceived: June 09, 2009; ac cepted:

Sep tem ber 09, 2009).

Key words: Po land, Holy Cross Moun tains, Lower Ju ras sic, di no saur crouch ing trace.

INTRODUCTION

A new di no saur-sit ting trace was found by two of us (G. D. G. and M. L.) at the Szydłówek site, in the Holy Cross Moun tains of Po land, in Au gust 2008. The first di no saur tracks at this lo cal ity were dis cov ered a year ear lier by Joanna Roszkowska, Urszula Meiss ner and Zbigniew Remin. Those pre vi ous finds were re ported by Niedźwiedzki and Remin (2008), and Niedźwiedzki et al. (2009). Tracks are found in the so-called “Szydłowiec Sand stones” mined in a small quarry lo cated at GPS co or di nates N 51°14.298’ and E 020°53.040’. “Szydłowiec Sand stones” (in for mal re gional lithostratigraphic unit) be longs to the Drzewica For ma tion of late Pliensbachian age and rep re sents the sixth se quence of the epicontinental Lower Ju ras sic de pos its in Po land. This part of Drzewica For ma tion rep re sents a suc ces sion com - prised of (from the old est to youn gest) nearshore-fore - shore-backshore/eolian fa cies (Pień kowski, 2004).

A few pre vi ous finds of sand stone slabs with di no saur foot - prints were de stroyed dur ing reg u lar quar ry ing ac tiv ity (e.g., Fig. 1A). How ever, most of the dis cov ered spec i mens, in clud - ing the one re ported here with the cat a logue num ber J484, were bought by Stowarzyszenie “Delta” (Delta As so ci a tion) and pro tected in the JuraPark theme park com plex in Bałtów (e.g.,

Fig. 1B–F). Spec i mens were re cently stored in a spe cially de - signed open-air ex hibit named Sabathówka, in me mo rial of late Pol ish palaeontontologist Karol Sabath.

Only five pre vi ously known spec i mens of crouch ing theropod tracks have been re ported in the lit er a ture. These spec i mens are from the Lower Ju ras sic of Mas sa chu setts (USA), St. George (Utah, USA) and the Lower or Mid dle Ju - ras sic of China (Gierliński, 1994; Lockley et al., 2003; Mi lan et al., 2008; Milner et al., 2009). A sixth, pre vi ously un doc u - mented spec i men, was dis cov ered in 2004 at a site in the Lower Ju ras sic Glen Can yon Group of the Glen Can yon (Lake Powell) Na tional Rec re ation area, Utah. This spec i men is il lus trated here for the first time (Fig. 2), but is not de scribed in de tail; a mold and rep lica are housed at the Uni ver sity of Col o rado at Den ver, in the Di no saur Tracks Mu seum (CU 183.84). Fi nally, the new Szydłówek find rep re sents the sev - enth ex am ple, and most im por tantly is among the most com - plete and best pre served.

TRACK DESCRIPTION

The di no saur-sit ting trace fos sil is pre served as a nat u ral cast on the fine-grained sand stone slab and as so ci ated with nu mer ous bi valve rest ing traces of Lockeia. The di no saur

SHORT COMMUNICATION

ichnite is com prised of an ischial trace (Fig. 3C), left and right pes (Fig. 3B), and left and right manus (Fig. 3A). The manus tracks are much smaller than the pes and slightly wider (5.0 cm) than long (4.5 cm). The manus is tridactyl and dig its in crease in length in the se quence: I, II, III. The ischial trace is tear-shaped, lon ger (12 cm) than wide (6.5 cm). The ischiadic cal los ity trace is lo cated al most mid way be tween the meta tar - sal prox i mal ends.

The pedal tracks are mesaxonic, tridactyl and plantigrade.

The phalangeal por tion of the foot print is 23 cm long, whereas the en tire foot print (in clud ing the metapodium) is 37 cm long.

An gles be tween the digit axes are: II–III = 13–18°, III–IV = 7–22°. The third pedal digit is the lon gest one. The ra - tio of the third pedal digit pro jec tion be yond the lat eral toes to the length of the pes phalangeal por tion equals 0.33. The ra tios of the dig its (en tire lengths) are: III/II = 1.17 and III/IV = 1.11.

How ever, these ra tios mea sured ac cord ing to the method of Olsen et al. (1998) are: III/II = 1.37 and III/IV = 0.89, which pos si bly re flect the ra tios of the com bined lengths of trackmaker pha lan ges III2 + III3 + III4 to II2 + II3 and IV1 + IV2 + IV3 + IV4 + IV5.

472 Gerard D. Gierliński, Martin G. Lockley and Grzegorz Niedźwiedzki

Fig. 1. Late Pliensbachian track as sem blage from Szydłówek, Po land

A — Parabrontopodus trackway; B — Anchisauripus sp.; C — Kayentapus sp.; D — Eubrontes sp.; E — Anomoepus trackway;

F — Moyenisauropus sp.

DISCUSSION

As shown as shown in Fig ure 2, the Glen Can yon spec i men is quite sim i lar in size and mor phol ogy to the Szydłówek find, al - though part of the right pes is miss ing. The pedal tracks are sim i lar in length (both spec i mens are ~40 cm, when in clud ing meta tar sal traces), and com prise ap prox i mately 50% of the to tal length, and are width about ~12 cm. The most no ta ble dif fer ences are that the

Glen Can yon tracks lack manus traces, but have clearer hallux traces. In ad di tion, the pes traces are more widely spaced and the right pes trace is lo cated an te rior to the left pes by the equiv a lent of about one-half of a track length (~20 cm).

The ra tios of pedal digit lengths in the new Pol ish spec i men (JuraPark J484) are sim i lar to those given by Olsen et al. (1998) for the ichnospecies Eubrontes giganteus and Anchisauripus sillimani, as well as for the foot mor phol ogy of the basal theropod gen era Coelophysis and Dilophosaurus. Thus, this is

A distinctive crouching theropod trace from the Lower Jurassic of Poland 473

Fig. 2. Theropod crouch ing trace (spec i men CU 183.84) from the Lower Ju ras sic, Glen Can yon Group, Utah

A — pes; B — hallux; C — other foot print of a large theropod (Eubrontes sp.)

a unique trace fos sil of a crouch ing ceratosaurian theropod with well-de fined man ual digit prints left by the hands, and with its palms fac ing ven trally, not me di ally like in the St. George spec - i men SGDS.18.T1 (see, Milner et al., 2009) .

The pres ence of a well-pre served man ual im print in the pre - vi ously de scribed squat ting theropod im pres sion, AC 1/1 from the Lower Ju ras sic of Mas sa chu setts (see, Gierliński, 1994), was later ques tioned by Lockley et al. (2003). Ac cord ing to the orig i nal in ter pre ta tion, the Mas sa chu setts spec i men shows man ual toe traces, which in crease in length in the se quence: I, II, III. The same fea ture is ob served in the pres ent spec i men from Po land. As noted by Gierliński (1994), this fea ture seems

im por tant in un der stand ing the or i gin of the Atreipus trackmaker (Olsen and Baird, 1986).

Atreipodids are dis tinc tive Late Tri as sic ichnites, which com bine a small theropod-like (grallatorid) pes with the prim i - tive archosaurian (chirotheriid) re duced, tridactyl or tetradactyl manus. Fur ther more, their man ual dig its in crease in length in the clearly dif fer ent se quence: I, IV, II, III. Olsen and Baird (1986) have ar gued that such a com bi na tion might have been made by a basal ornithischian trackmaker, How ever, later au - thors, such as Thulborn (1990, 1993) and Weems (1992), sug - gested a theropod or i gin for those ichnites.

474 Gerard D. Gierliński, Martin G. Lockley and Grzegorz Niedźwiedzki

Fig. 3. Theropod crouch ing trace (spec i men JuraPark J484) from the late Pliensbachian of Szydłówek, Po land A — manus; B — pes; C — ischial cal los ity trace

Re cent dis cov er ies sup port the hy poth e sis of Olsen and Baird (1986), Gierlinski (1994), and Milner et al. (2009) on the non-theropod af fin ity of the Atreipus trackmaker. It is also note wor thy that a po ten tial atreipodid trackmaker can di date has al ready been found: an ornithischian-like dinosauromorph, such as the re cently-dis cov ered Silesaurus from the Up per Tri -

as sic of Po land (Dzik, 2003). Silesaurus is a small, non-theropod, quad ru ped with a theropod-like pes. More over, Atreipus footprins were re cently found in the Up per Tri as sic strata of Po land (Fig. 4).

REFERENCES

DZIK J. ( 2003) — A beaked her biv o rous archosaur with di no saur af fin i - ties from the early late Tri as sic of Po land. J. Vertebr. Paleont., 23 (3):

556–574.

GIERLIŃSKI G. (1994) — Early Ju ras sic theropod tracks with the meta - tar sal im pres sions. Prz. Geol., 42 (4): 280–284.

LOCKLEY M., MATSUKAWA M. and LI J. (2003) — Crouch ing theropods in tax o nomic jun gles: ichnological and ichnotaxonomic in - ves ti ga tions of foot prints with meta tar sal and ischial im pres sions.

Ichnos, 10 (1): 169–177.

MILƒN J., LOOPE D. B. and BROMLEY R. G. (2008) — Crouch ing theropod and Navahopus sauropodomorph tracks from the Early Ju ras - sic Na vajo Sand stone of USA. Acta Palaeont. Pol., 53 (2): 197–205.

MILNER A. R. C., HARRIS J. D., LOCKLEY M. G., KIRKLAND J. I. and MATTHEWS N. A. (2009) — Bird-like anat omy, pos ture, and be hav - ior re vealed by an Early Ju ras sic theropod di no saur rest ing trace. PLoS ONE, 4 (3): e4591.

NIEDZWIEDZKI G. and REMIN Z. (2008) — Gi gan tic theropod di no saur foot prints from the up per Pliensbachian of the Holy Cross Moun tains, Po land (in Pol ish with Eng lish sum mary). Prz. Geol., 56 (9): 823–825.

NIEDZWIEDZKI G., REMIN Z., ROSZKOWSKA J. and MEISSNER U.

(2009) — New finds of di no saur tracks in the Li assic strata of the Holy Cross Moun tains, Po land (in Pol ish with Eng lish sum mary). Prz.

Geol., 57 (3): 252–262.

OLSEN P. E. and BAIRD D. (1986) — The ichnogenus Atreipus and its sig nif i cance for Tri as sic biostratigraphy. In: The Be gin ning of the Age of Di no saurs: Fau nal Change Across the Tri as sic-Ju ras sic Bound ary (ed. K. Padian): 61–87. Cam bridge Uni ver sity Press. Cam bridge.

OLSEN P. E ., SMITH J. B. and Mc DON ALD N. G. (1998) —The ma te rial of the spe cies of the clas sic theropod foot print gen era Eubrontes, Anchisauripus and Grallator (Early Ju ras sic, Hart ford and Deerfield bas ins, Con nect i cut and Mas sa chu setts, U.S.A.). J. Vertebr. Paleont., 18 (3): 586–601.

PIEŃKOWSKI G. (2004) — The epicontinental Lower Ju ras sic of Po land.

Pol. Geol. Inst. Spec. Pap., 12.

THULBORN R. A. (1990) — Di no saur tracks. Chap man and Hall, Lon don.

THULBORN R.A. (1993) — A tale of three fin gers: ichnological ev i dence re veal ing the homologies of man ual dig its in theropod di no saurs. In:

The Nonmarine Tri as sic (eds. S. G. Lucas and M. Mo rales). New Mex - ico Mus. Nat. Hist. Sc. Bull., 3: 461–263.

WEEMS R. E. (1992) — A re-eval u a tion of the tax on omy of New ark Supergroup saurischian di no saur tracks, us ing ex ten sive sta tis ti cal data from a re cently ex posed tracksite near Culpeper, Vir ginia. In:

Proc. 26th Fo rum on the Ge ol ogy of In dus trial Min er als (ed. P. C.

Sweet). Vir ginia Di vi sion of Miner. Res. Publ., 119: 113–127. Char - lottes ville.

A distinctive crouching theropod trace from the Lower Jurassic of Poland 475

Fig. 4. Atreipus sp. from the Up per Tri as sic of Woźniki near Częstochowa, Po land, the spec i men found and owned by G. N.