sign in sign up
<<
Home , Carnic Prealps, Lagosuchus, Ornithichnites, Sacisaurus, Staurikosaurus, Technosaurus

Bollettino della Società Paleontologica Italiana, 53 (1), 2014, 1-18. Modena

New tracks from the Dolomia Principale (Upper ) of the (-Venezia Giulia, NE )

Marco Marzola & Fabio Marco Dalla Vecchia

M. Marzola, CICEGe/GeoBioTec, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, P-2829-516 Caparica, Portugal; Museu da Lourinhã, Rua João Luís de Moura 95, 2530-158 Lourinhã, Portugal; [email protected] F.M. Dalla Vecchia, Institut Català de Paleontologia “M. Crusafont” (ICP), Grup de Recerca del Mesozoic, C/Escola Industrial 23, E-08201 Sabadell, Spain; [email protected]

KEY WORDS - Dinosaur tracks, tridactyl footprints, Anchisauripus, Dolomia Principale, Parco Dolomiti Friulane, Upper Triassic, Italy.

ABSTRACT - Ten new track-bearing boulders discovered in the Parco Naturale delle Dolomiti Friulane area (Carnic Prealps, NE Italy) during the last 15 years demonstrate that bipedal with a functionally tridactyl, digitigrade pes, within the size-class of the ichnogenus Anchisauripus Lull, 1904, were the most common trackmakers in the carbonate tidal flats of the Dolomia Principale during the latest Triassic. If the footprint morphology actually reflects the functional tridactyl condition of the trackmakers’ feet, theropods are the most suitable trackmakers. The ichnoassociation of the Parco delle Dolomiti Friulane area differs from coeval ichnoassociations in the dominance of mid-sized tridactyl footprints and the rarity of small tridactyl (Grallator Hitchcock, 1858; length <15 cm) and chirotheriid tracks. Tracks potentially produced by basal sauropodomorphs, which were the most common European dinosaurs in the late -Rhaetian interval, are underrepresented.

RIASSUNTO - [Nuove orme di dinosauro nella Dolomia Principale (Triassico Superiore) delle Prealpi Carniche (Friuli-Venezia Giulia, Italia nord-orientale)] - In questo lavoro vengono descritti dieci nuovi massi con orme fossili rinvenuti negli ultimi 15 anni nel Parco Naturale delle Dolomiti Friulane (Prealpi Carniche, Italia nord-orientale). Questi nuovi reperti, inquadrati nel contesto icnologico del Triassico Superiore del Parco delle Dolomiti Friulane, confermano che i dinosauri bipedi con un pes funzionalmente tridattile e digitigrado erano i più comuni autori di orme sulle piane tidali carbonatiche della Dolomia Principale durante il Triassico Superiore. Questi dinosauri producevano orme lunghe tra i 15 e i 25 centimetri, tipiche della classe dimensionale dell’icnogenere Anchisauripus Lull, 1904. Se la morfologia delle orme riflette realmente la tridattilia funzionale del pes del trackmaker, i dinosauri teropodi sono i più probabili candidati. I potenziali autori alternativi bipedi o facoltativamente tali (arcosauri pseudosuchi, dinosauromorfi non dinosauri, ornitischi basali, saurischi basali, sauropodomorfi basali) erano troppo piccoli rispetto alle orme in esame. Inoltre, quando presenti nel record fossile attuale, le loro zampe posteriori presentano un dito I sensibilmente lungo, che toccava il suolo e poteva produrre orme tetradattili. L’icnoassociazione del Parco delle Dolomiti Friulane si distingue dalle altre icnoassociazioni coeve per l’abbondanza di orme tridattili di medie dimensioni (lunghe 15-25 cm) e la rarità di quelle più piccole e delle orme chirotheriidi. Anche le impronte riferibili ai sauropodomorfi basali, i dinosauri più comuni in Europa durante il Norico superiore-Retico, sono poco rappresentate.

INTRODUCTION footprint record also in the nearby of the Veneto Region and Bolzano/Bozen Autonomous Province The Parco Naturale delle Dolomiti Friulane (Natural Park (Mietto, 1988; Leonardi, 2000; Belvedere et al., 2008). of the Friulian Dolomites; PNDF) extends in the western part This paper deals with the tracks discovered in the of the Carnic Prealps (Pordenone Province, Friuli-Venezia PNDF during the last 15 years, which have not yet been Giulia Autonomous Region, northeastern Italy). The Late reported in the literature. Triassic Dolomia Principale is a formation that crops out The aim of this study is: 1) the description of extensively in the Park area and has yielded a relatively unpublished new material and comparison with similar abundant record of tetrapod footprints (Dalla Vecchia & ichnotaxa, 2) the identification of possible trackmakers Mietto, 1998; Dalla Vecchia, 2002, 2006). These are usually and 3) the understanding of the overall ichnoassemblage found on the surface of large boulders fallen down from and its contextualization within the latest Triassic tetrapod steep slopes and cliffs. Most of the footprints were initially tracks record. referred to theropod dinosaurs, a few have been attributed to “prosauropods” (= basal of recent phylogenetic analyses; e.g., Upchurch et al., 2007; Ezcurra, PROVENANCE AND GEOLOGICAL REMARKS 2010) and to crurotarsal (Dalla Vecchia & Mietto, 1998). Later, Dalla Vecchia (2002, 2006, 2008) emphasized The new track-bearing boulders are located in the that the tridactyl footprints previously referred to theropod Settimana Creek Valley and in the southern slope of Mt dinosaurs could have been produced by herrerasaurids, Caserine Basse north of the Grave di Gere locality, both that according to some phylogenetic hypotheses (e.g., of Claut municipality, and in the Pezzeda Creek Valley of Langer, 2004), are basal, non-theropod saurischians with a Cimolais municipality (Fig. 1). Geographic coordinates functionally tridactyl pes. are reported for each boulder. The Dolomia Principale (Hauptdolomit of German- Most of the lithostratigraphic units cropping out in speaking authors) has yielded a relatively rich tetrapod the PNDF originated from carbonate sediments deposited

ISSN 0375-7633 doi:10.4435/BSPI.2014.01 2 Bollettino della Società Paleontologica Italiana, 53 (1), 2014

Fig. 1 - Map with position of the study area and the track-bearing boulders. Abbreviations: AVG1-3 = unnamed creek in the southern slope of Mt Caserine Basse north of the Grave di Gere locality, boulders 1-3; VPE1 = Pezzeda Creek Valley boulder; VSE1-6 = Settimana Creek Valley, boulders 1-6. in marine environments during the and the late Norian-Rhaetian Calcare del Dachstein in the the (Carulli et al., 2000; Carulli, 2006). The northern part of the Carnic Prealps, while it fades into the Dolomia Principale, Calcare del Dachstein, and Calcari supposedly Calcari Grigi in the southern Grigi are the only units deposited in shallow carbonate part; thus, in this area the Dolomia Principale should be platform settings, while others represent deeper settings Norian to Rhaetian in age (Pisa in Braga et al., 1971; (slope, basin, and submarine plateau). The outcrops of the Carulli et al., 2000). Calcare del Dachstein are very limited in the PNDF area Bosellini & Hardie (1988) informally divided the (environs of Cima Ladice) and the Calcari Grigi crops out Dolomia Principale of the western Carnic Prealps into only in the southern part of the Carnic Prealps and in the three units: a lower unit (400-500 m-thick) characterised Mt Raut (Carulli et al., 2000). The Dolomia Principale by shallowing-upward, metric peritidal cycles capped crops out at all locations where the new footprint-bearing by stromatolite horizons; a middle unit characterised by boulders have been found; the observed lithology and diagenetic cycles (about 300 m-thick); and an upper unit all sedimentological features of the boulders support the (150-200 m-thick) similar to the lower unit. Particularly attribution to this lithostratigraphic unit, as it is the case important for the preservation of the footprints in the with the other footprints found in the PNDF (Dalla Vecchia Dolomia Principale are the intertidal stromatolite intervals & Mietto, 1998; Dalla Vecchia, 2006). (Mietto, 1988; Dalla Vecchia & Mietto, 1998). In northern Italy, the Dolomia Principale crops out Because the new boulders are mostly found in the from Lombardy to the eastern Friuli and is dated as late debris along the creeks, their exact original stratigraphical to Norian (Berra et al., 2007; Neri et al., 2007). position in the Dolomia Principale is unknown, as it is the It is mainly composed of light gray to whitish dolostone case with the other boulders described by Dalla Vecchia and its thickness varies from 250 m in the Adige Valley & Mietto (1998). up to 2000 m in Cadore and in the Carnic Prealps (Bosellini, 1967; Bosellini & Hardie, 1988; Carulli et al., 2000). The depositional environment was a wide, muddy, MATERIALS AND METHODS carbonate tidal flat with characteristic cyclical alternance of supratidal-intertidal-subtidal facies (Bosellini, 1967; The studied material includes ten track-bearing Bosellini & Hardie, 1988). boulders containing a total of at least 56 footprints with a The lower boundary of the Dolomia Principale is not degree of preservation from very poor to moderately good. exposed in the PNDF area; its upper boundary is with We use the acronyms AVG1-3 to identify the boulders 1-3 M. Marzola & F.M. Dalla Vecchia - Triassic dinosaur tracks from the Carnian Prealps 3 from an unnamed creek along the southern slope of Mt by a medium size (15-25 cm long), the trace of digit III Caserine Basse just north of the Grave di Gere locality, that “projects relatively further anteriorly than in VPE1 for the boulder from Pezzeda Creek Valley, and but not as far as in Grallator (digit III projection ratio >1.3 VSE1-6 for the boulders 1-6 from the Settimana Creek and <1.8)”, the footprint length/width ratio near 2, and the Valley (Fig. 1). total digital divarication in the range 20°-35°. Grallator All footprints identified on those boulders appear to be (Olsen et al., 1998, p. 595) is characterised by a small size tridactyl and mesaxonic; in no case the trace of another (<15 cm long), the trace of digit III that “projects relatively foot is associated with the tridactyl footprint to form a further anteriorly ... than in Eubrontes and Anchisauripus”, manus-pes couple. the footprint length/width ratio near or greater than 2, and Measurement of interdigital angles was carried out the total digital divarication in the range 10°-30°. following Thulborn (1990, fig. 4.5). Pace length was The total digital divarication depends greatly on the measured as far as possible between the proximal ends of conditions of the substrate (Gatesy et al., 1999; Manning, digit III traces. The height at the hip was calculated using 2004; Diàz-Martínez et al., 2009); this must be considered the morphometric ratios method by Thulborn (1990, p. in the comparison between the type material of Grallator, 251) and absolute speed using the equation of Alexander Anchisauripus, and Eubrontes from the Lower Jurassic (1976). Tridactyl footprints are identified as right or left continental sandstones of North America and the footprints pedes according to characteristic features of digit IV. In from PNDF. The Triassic ichnogenus Coelurosaurichnus fact, the trace of digit IV of the pes in dinosaurian tridactyl von Huene, 1941 is considered a junior synonym of footprints often includes the imprint of a robust metatarsal Grallator (see Leonardi & Lockley, 1995; Klein & Lucas, pad, thus projecting more posteriorly than the trace of 2010). The Triassic ichnogenus Atreipus Olsen & Baird, digit II, causing a typical posteromedial indentation (sensu 1986 is based on tridactyl mesaxonic pes imprints similar in Pittman, 1989). All measurements are reported in Tab. 1. size (pes print ranging 9-14 cm according to those authors) Some footprints have been photographed during night and morphology to Grallator that are associated with a with artificial illumination to increase their visibility. Track small, tri- to tetradactyl manus imprint (see also Haubold outlines were drawn onto transparent acetate film from the & Klein, 2002; Safran & Rainforth, 2004; D’Orazi original material and drawings of the single footprints were Porchetti et al., 2008). Haubold & Klein (2000) erected traced on photographs of the cast with direct control of the the Grallator-Atreipus plexus for grallatorid footprints of morphology on the cast changing the lighting to emphasize trackways produced by facultative bipedal trackmakers. particulars and then redrawn on transparent film. Casts The tridactyl footprints from PNDF are compared to those were taken from eight specimens; those of VSE1-1, VSE2- ichnotaxa. 1A and VSE2-1B, VSE3 and VSE5 are stored at the Museo Also the ichnogenus Anomoepus Hitchcock, 1848 has a Friulano di Storia Naturale (Udine, Italy) under repository tridactyl pes imprint associated with a manus imprint, but numbers MFSN cal-073 to 077, respectively, while those of the latter is pentadactyl, the pes has a higher total digital VSE2-1A, VPE1-1A, AVG1-2B and AVG1-1 are deposited divarication (~70°), and the trace of digit III projects at the Laboratorio “L’Occhione” of the Associazione only slightly beyond those of digits II and IV. Although Naturalistica Cordenonese (Cordenons, Italy) under Anomoepus is a typical Early Jurassic ichnogenus (Olsen repository numbers LOC-01 to 04. In order to illustrate & Rainforth, 2003; Lockley & Gierliński, 2006), it is also the footprint morphology, photographs of the casts were used for comparison and discussion here. taken under different illumination. The photograph of the footprint VSE5 has been elaborated to 3D by the software Agisoft PhotoScan. DESCRIPTION AND COMPARISON Ichnological abbreviations: AII-III and AIII-IV = OF THE MATERIAL interdigital divarication II-III and III-IV; AII-IV = total digital divarication; ANG = pace angulation; FL = footprint Settimana Creek Valley length; FW = footprint width; h = height at the hip; LII- Boulder VSE1 - (620 m a.s.l. at the confluence of IV = length of digits II-IV prints; PL = pace length; SL = the Culisei Creek; Gauss Coordinates, obtained by GPS: stride length; Te = toe extrusion (sensu Weems, 1992); V 46.29°N, 12.50°E) (Fig. 2a). = absolute speed. This boulder contains two poorly preserved tracks that are shallow negative epireliefs surrounded by broad expulsion rims. VSE1-1 is the better preserved of the two ICHNOTAXONOMIC REMARKS and tridactyl (Fig. 2b-c). VSE1-2 is just a depression with a triangular outline without clear digit traces which actual Klein & Haubold (2007), Klein & Lucas (2010), morphology is concealed by the infilling by the overlaying and Klein et al. (2011) referred tridactyl mesaxonic bed; however, its posterior part has the same outline as footprints from the Upper Triassic produced by bipedal VSE1-1, so it is probably another tridactyl footprint. VSE1- trackmakers to the ichnogenera Grallator Hitchcock, 1858 1 is about 22 cm long and moderately elongated (FL/FW and Eubrontes Hitchcock, 1845. These ichnogenera and = 1.57), AII-IV is moderately high (44°) and Te is about Anchisauripus Lull, 1904 have been diagnosed by Olsen et 8.5 cm. The distal portion of the impression of digit III is al. (1998) based on specimens from the Lower Jurassic of slightly curved and its end seems to be pointed. The traces northeastern USA. Eubrontes (Olsen et al., 1998, p. 590) of the outer digits do not have clearly defined margins; the is characterised by a large size (>25 cm long), a “broad left one is shorter than the right one but more posteriorly pes” and a total digital divarication averaging 25°-40°. elongated. Therefore, the former probably represents the Anchisauripus (Olsen et al., 1998, p. 592) is characterised digit IV and the footprint can be identified as a left one. 4 Bollettino della Società Paleontologica Italiana, 53 (1), 2014

VSE1-1 VSE2-1A VSE2-1B VSE3 VSE4 VSE5 VSE6 AVG1-1

Right/left left right right left - right ?left ?left

FL 22 21.5 >17.5 17.3 22 9 25.7 13.5

FW 14 14 12.5 13.8 18 6.3 18.4 8.4

FL/FW 1.57 1.54 >1.40 1.25 1.22 1.43 1.4 1.61

h(1) 101.2 98.75 - 79.6 101.2 41.4 118.2-146.5 62.1

h(2) 99 96.75 - 77.85 99 40.5 125.9-115.7 60.75

LII ~12.5 11 ~ 9 7.7 11.3 (12.2) 4.9 8.3 -

LIII ~13 ~15 >11 13 11.3 8 17.7 -

LIV ~11 16.5 - 9.5 12.2 (11.3) 5.3 11.2 ? -

AII-III 20 17 12 15 10 (9) 21 21 -

AIII-IV 24 15 16? 32 9 (10) 26 13 (32*) -

AII-IV 44 32 28? 47 19 47 34 (53*) -

Te ~8.5 6 - 8.2 5.6 4.3 8.7 -

Te/FW ~0.61 0.43 - 0.59 0.31 0.68 0.47 -

(FL-Te)/FW ~0.96 1.11 - 0.66 0.91 0.75 0.92 -

Tab. 1 - Main measurements and ratios of tridactyl footprints, with relative estimates of the heights at hip. Lengths and widths are in centimeters, angles are in degrees. Data not available are indicated by ‘-’; h(1) estimates are those considering the trackmaker as a generic bipedal dinosaur, while h(2) estimates are those considering the trackmaker as a theropod; the alternative measurement of AIII-IV and the consequent value of AII-IV in VSE6 is marked by *. For footprints with FL at the boundary between two size classes (i.e., around 25 cm), h estimates are reported for both classes based on Thulborn (1990, 8.2-3 and 8.6-7).

AVG1-2B AVG1-3B AVG2-1B AVG2-2A AVG2-3 AVG2-4 AVG3 VPE1-2 B

Right/left left right left? left - - left ?left

FL 13.5 13 18 21 18 20.5 25.1 20.3

FW 8.7 8 - 12.5 18 13 16.8 16

FL/FW 1.55 1.62 - 1.68 1 1.58 1.49 1.27

h(1) 62.1 59.8 82.8 96.6 82.8 94.3 115.5-143.1 93.4

h(2) 60.75 58.5 81 94.5 81 92.25 113-123 91.35

LII ------11.8 ?8.5

LIII ------20 14

LIV ------19.3 12.5

AII-III ------15 23 (22)

AIII-IV ------16 21 (23)

AII-IV ------31 44

Te ------7.8 6.68

Te/FW ------0.46 0.42

(FL-Te)/FW ------1.03 0.85

Tab. 1 - Continuation. M. Marzola & F.M. Dalla Vecchia - Triassic dinosaur tracks from the Carnian Prealps 5

Fig. 2 - Boulder VSE1. a) Photograph of footprints VSE1-1 and VSE1-2; b) photographs of the cast of footprint VSE1-1 (left, light from the top left; right, light from the top right); c) and interpretative drawing of the footprint VSE1-1, based on the cast and mirrored. IV = trace of digit IV. Scale bar: 10 cm in a, 5 cm in b and c.

Boulder VSE2 - (745 m a.s.l.; Gauss Coordinates, VSE2-1A is a right footprint 21.5 cm long and obtained by GPS: 46.31°N, 12.53°E) (Fig. 3). moderately elongate (FL/FW = 1.54). AII-IV is moderately This boulder was used to build the levee of the right low (41°) and the toe extrusion of digit III is also moderate bank of the Settimana Creek Valley. It is made up of whitish (Te = 6 cm). Digit traces are relatively slender; digits IV dolostone with barely visible sub-millimetric lamination, is the longest and digit II the shortest (Tab. 1). The digit representing a stromatolite level. The footprint-bearing traces taper distally, although no clear claw traces can be surface is 250 cm long and 160 cm wide and shows distinguished. The trace of digit III is slightly sigmoid; small mud cracks. Two tridactyl footprints (VSE2-1A and digit II is straight with two rounded phalangeal pad VSE2-1B) are preserved as concave epireliefs and appear impressions; digit IV is probably deformed by lateral mud to be consecutive footprints in a trackway. collapse and shows a clear rounded trace of the metatarso-

Fig. 3 - Boulder VSE2. a) Photograph of consecutive footprints VSE2-1A and VSE2-1B under artificial light; b-c) footprint VSE2-1A, photograph of the cast (b, light from the left) and interpretative drawing (c, based on the cast and mirrored); d-e) footprint VSE2-1B, photograph of the cast (d, light from the left) and interpretative drawing (e, based on the cast and mirrored). IV = trace of digit IV. Scale bar: 5 cm. 6 Bollettino della Società Paleontologica Italiana, 53 (1), 2014

Fig. 4 - Boulder VSE3. a) Photograph of the footprint VSE3; b) photograph of the cast of the footprint (light from the left); c) interpretative drawing (based on the cast and mirrored). IV = trace of digit IV. Scale bar: 5 cm. phalangeal pad. The posteromedial indentation (sensu The trace of digit II projects less posteriorly than that Pittman, 1989) is evident (Fig. 3b-c). of digit IV, causing a posteromedial indentation (sensu The state of preservation of VSE2-1B is worse than Pittman, 1989) of the footprint. The footprint is scarcely VSE2-1A. Although it is apparently the subsequent trace elongated (FL/FW about 1.25), but digit III is much longer of the latter, its congruent morphology suggests another than the other two and largely projecting beyond their right footprint. If this is the case, the left footprint is distal ends (Te is 82 mm). AII-IV is moderately high (47°). missing. Only the two proximal digital pad traces of digit III are evident, while the distal part of the digit is only Boulder VSE4 - (745 m a.s.l.; Gauss Coordinates, partly preserved. This makes the footprint rather short obtained by GPS: 46.31°N, 12.53°E) (Fig. 5). (17.5 cm in length). The impression of digit IV is poorly This boulder was also used to build the levee of the defined but seems to end proximally with a rounded right bank of the Settimana Creek Valley; it is located a few metatarso-phalangeal pad that is connected to another meters upstream from VSE3. It is composed of pale gray rounded pad placed in a posteromedial position. The dolostone with barely visible submillimetric lamination. trace of digit II is shorter and broader than that of digit The footprint-bearing surface is 250 cm long and 150 cm IV, with two pad prints, the distal one being larger than wide. A single, poorly preserved, tridactyl and mesaxonic the proximal one. footprint 22 cm long is preserved as a concave epirelief (Fig. 5a). It is scarcely elongated (FL/FW is 1.22) and Boulder VSE3 - (745 m a.s.l.; Gauss Coordinates, AII-IV is rather low (19°). The trace of digit III is straight, obtained by GPS: 46.31°N, 12.53°E) (Fig. 4). relatively short and distally rounded. The left outer digit This boulder was also used to build the levee of the trace is curved outward (Fig. 5b). right bank of the Settimana Creek Valley; it is located about 40 meters upstream from VSE2. It is composed Boulder VSE5 - (750 m a.s.l.; Gauss Coordinates, of whitish dolostone with barely visible submillimetric obtained by GPS: 46.31°N, 12.53°E) (Fig. 6). lamination like the boulder VSE2, but without mud cracks. This boulder measures 70 x 60 x 60 cm and is made The footprint-bearing surface is 250 cm long and 250 cm of a massive basal portion, probably corresponding to the wide. A single tridactyl footprint of the left pes, 17.3 cm long, is preserved as a concave epirelief (Fig. 4a-b). The presence of an associated manus print can be excluded with confidence because the state of preservation is relatively good (Fig. 4a) and the surface is smooth. Digit III is straight and 130 mm long, with the impressions of three phalangeal pads, a smaller, possible phalangeal- metatarsal pad and a small, rounded, claw trace; the distal portion partly preserves the infilling by the overlying bed. Digit II is short (77 mm), with (possibly two) pad prints and a long claw trace directed anteromedially. The trace of digit IV is shallower and less defined than the other two, which are 8 mm deep at maximum; it is 95 mm long, with a broad and rounded phalangeal-metatarsal pad print and a Fig. 5 - Boulder VSE4. a) Photograph of the footprint VSE4; b) small rounded claw trace which is directed anterolaterally. interpretative drawing. Scale bar: 5 cm. M. Marzola & F.M. Dalla Vecchia - Triassic dinosaur tracks from the Carnian Prealps 7

Fig. 6 - Boulder VSE5. a) Photograph of the footprint VSE5; b) 3D image; c) interpretative drawing (based on the cast and mirrored); d) photo of the cast with light from the left (left) and from the right (right). IV = trace of digit IV. Scale bar: 5 cm. subtidal interval of a depositionary cycle in the Dolomia a broader proximal portion that continues distally with a Principale and an upper weakly laminated portion, straight and narrow groove; if the actual digital trace is the probably representing an intertidal stromatolite facies. broader one, it is 5.3 cm long and slightly bent medially The surface at the top of the laminate set shows a single, and the footprint is 6.5 cm long, while including the groove shallow footprint preserved as a concave epirelief (Fig. the digital trace is 8 cm long. The traces of digits II and 6a). It is a small (9 cm maximum length) right tridactyl IV are 4.9 and 5.3 cm long respectively, and taper slightly footprint. The 3D image (Fig. 6b) shows that the trace of distally with rounded ends. There is a posteromedial digit II is deeper than that of digit IV and III. Digits III and indentation. AII-IV is moderately high (47°). IV are straight, while digit II is markedly bent medially. Considering its maximum possible length, the footprint The actual extent of the digit III trace is unclear. There is is moderately elongated (FL/FW is 1.43) with digit III 8 Bollettino della Società Paleontologica Italiana, 53 (1), 2014 trace being much longer than the other two and projecting AVG1-2A to C is a trackway segment composed by far beyond their distal ends (Te = 4.3 cm). Considering the three consecutive footprints. PL is 35 cm, SL is 69 cm, and shorter option, the footprint would be practically as wide ANG is 170°. AVG1-2B is the best preserved footprint; it as long (FL/FW would be 1.03) and digit III trace would is 13.5 cm long and moderately elongated (FL/FW = 1.55). be very scarcely projecting far beyond the distal ends of Its outline is poorly defined, but the narrow and straight the other two digits (Te = 1.5 cm). trace of digit III projecting forward is evident. The straight trace of an outer digit, which is elongated backward (Fig. Boulder VSE6 - (650 m a.s.l.; Gauss Coordinates, 8c), can be identified as digit IV, in agreement with the obtained by GPS: 46.29°N, 12.50°E) (Fig. 7). position of the footprint in the trackway. This boulder measures 50 x 40 x 15 cm and is AVG1-3A to D is probably a trackway segment composed of light gray, massive dolostone. Its lower because AVG1-3A, AVG1-3B, and AVG1-3D are arranged surface shows a very poorly preserved, relatively large in a row. However, there is no evidence of a preserved (FL is 25.7 cm) tridactyl footprint as a convex hyporelief footprint between AVG1-3B and AVG1-3D that cannot (Fig. 7a). It is probably a left footprint, because the trace be consecutive footprints because the gap between them of the left digit has a posterior phalangeal-metatarsal pad, is too large; PL between AVG1-3A and AVG1-3B is 37 indicating digit IV. This is one of the largest tracks found cm, while the distance between AVG1-3B and AVG1- so far in the PNDF, the largest being that from the Casera 3D is 65 cm. As in AVG1-2, footprints are tridactyl and Cjasavent locality (35 cm long; Dalla Vecchia & Mietto, mesaxonic, but the poor state of preservation prevents 1998). It is scarcely elongated (FL/FW about 1.40) and further morphological description. AVG1-3B is 13 cm the total digital divarication is 39° (if AIII-IV is measured long and moderately elongated (FL/FW = 1.62). based on the distal part of digit IV) or 53° (if AIII-IV is AVG1-1 has the same size (FL= 13.5 cm) and the same measured based on the chord of the whole, curved trace general morphology as AVG1-2B (Fig. 8d). It is also a left of digit IV). Digit III is slightly sigmoid in shape and the footprint and moderately elongated (FL/FW = 1.61). The supposed digit IV is curved medially (Fig. 7b). probable trace of a mud crack comes out from the proximal termination of the impression of digit IV. Unnamed creek, southern slope of Mt Caserine Basse Boulder AVG1 - (1390 m a.s.l.; Gauss Coordinates, Boulder AVG2 - (1500 m a.s.l.; Gauss Coordinates, obtained by GPS: 46.16°N, 12.35°E) (Fig. 8). obtained by GPS: 46.18°N, 12.37°E) (Fig. 9). This boulder is located in the “Ciolòn” locality. It This boulder measures 250 x 130 x100 cm and is made is made up of whitish dolostone with barely visible up of whitish dolostone with submillimetric lamination. submillimetric lamination. The exposed top surface of The lower surface of the boulder shows 18 tracks the boulder measures 240 x 140 cm and presents several preserved as convex hyporeliefs (casts); two consecutive concave epireliefs among which at least a dozen can footprints (AVG2-1A to B) and a trackway (AVG2-2A to be identified as tridactyl footprints. Some of them are C) can be distinguished in the sample (Fig. 9b). organized into two short trackway segments. All the AVG2-1A preserves only its distal part, the long digit footprints are poorly-preserved, and thus measurements III print having a remarkably protruding relief. AVG2-1B are only indicative. is apparently didactyl and probably a left footprint, 18 cm

Fig. 7 - Boulder VSE6. a) Photograph of the boulder with footprint under artificial light from the left (the footprint is enlightened with a broken ellipsoid line and all the three digits are marked). b) Interpretative drawing. II = trace of digit II; III = trace of digit III; IV = trace of digit IV. Scale bar: 5 cm. M. Marzola & F.M. Dalla Vecchia - Triassic dinosaur tracks from the Carnian Prealps 9

Fig. 8 - Boulder AVG1. a) Photograph of the footprint-bearing surface; b) interpretative map; c) AVG1-2B, photo of the cast with light from the left (left) and from the right (right); d) AVG1-1, photo of the cast with light from the left (left) and from the right (right). Scale bar: 10 cm in a, 30 cm in b, 5 cm in c and d. long, with the trace of digit IV missing. PL is 56 cm. It is are relatively broad and taper in the distal part, but probably a poorly preserved tridactyl track, as suggested without pointed claw marks. The trace of digit III is also by AVG2-1A. more protruding than those of the other digits (Te about The trackway AVG2-2A to C is composed of three 7.8 cm) and flares strongly in its middle-distal part. The consecutive footprints. AVG2-2A is the better preserved trace of a mud crack comes out from the posterior end of in the whole sample; it is a tridactyl left pes impression, the rounded metatarso-phalangeal pad trace of digit IV 21 cm long and relatively elongated (FL/FW = 1.68). PL similar to AVG1-1. is 81.40 and 70.70 cm (mean 76.10 cm), SL is 151 cm, and ANG is 174°. The poor state of preservation prevents Pezzeda Creek Valley reliable comparisons with known tridactyl ichnotaxa. Boulder VPE1 - (940 m a.s.l.; Gauss Coordinates, The track AVG2-3 is tridactyl and mesaxonic with a obtained by GPS: 46.33°N, 12.48°E) (Fig. 11). possible posterior sliding trace. It is 18 cm long (excluding This is a large boulder of banded dolostone made up the sliding trace) and 18 cm wide, so it is as long as wide of an alternance of massive and laminated sets. Footprints (FL/FW = 1.00). The total digital divarication II-IV is are preserved at the top of a laminated set. It is exposed high (95°). on the bed of Pezzeda Creek Valley, possibly fallen from The track AVG2-4 is tridactyl and mesaxonic with an the mountain wall hanging over the creek. The boulder unusually short digit III trace (see Fig. 9b). It is 20.5 cm contains a trackway composed of four shallow, tridactyl long and relatively elongated (FL/FW = 1.58). The free footprints preserved as concave epirelief. portions of the digit traces are quite short compared with VPE1-1B and C are the better defined footprints of the total track length and preserve claw marks. the trackway. VPE1-1B is 20.3 cm long and scarcely The isolated footprints AVG2-5 to 11 all appear to be elongated (FL/FW is 1.27). AII-IV is relatively high tridactyl with a length of about 20 cm (Fig. 9b). (44°) and the toe extrusion of digit III is moderate (Te = 6.68 cm). The right digit trace seems to project more Boulder AVG3 - (1520 m a.s.l.; Gauss Coordinates, posteriorly than the left one (Fig. 11b), as usual for digit obtained by GPS: 46.18°N, 12.37°E) (Fig. 10). IV, suggesting that this is a right footprint. However, it is This boulder measures 110 x 100 x 100 cm and is a left one according to its position in the trackway. The made up of grayish-white dolostone with submillimetric digital imprints taper apically, but there are no sharply lamination. It preserves a tridactyl footprint as convex pointed claw impressions. The trace of digit III is straight hyporelief. It is relatively large (FL = 25.1 cm) and and preserves the prints of three rounded pads plus a moderately elongated (FL/FW = 1.49), with a low total triangular distal impression. The trace of digit II is also digital divarication II-IV (31°). The traces of the digits straight and preserves the prints of a broad proximal pad, 10 Bollettino della Società Paleontologica Italiana, 53 (1), 2014

Fig. 9 - Boulder AVG2. a) Photograph of the footprint-bearing surface under artificial light (from the right) in perspective view; b) interpretative map. Scale bar: 20 cm. Notice relatively short digit III and elongated heel in AVG2-4, possibly indicating incomplete chirotheriid or other tetradactyl to pentadactyl forms. two or three traces of smaller successive pads and a faint tetrapod ichnites should be strictly based on anatomical triangular distal trace; the proximal pad is contiguous with features that, especially in poorly preserved tracks, are an elongated “heel” print. The trace of digit IV is short hard to recognize. and broad with two pad prints and a faint, short ungual impression. The footprints seem to be lined up: the mean Remarks on the new track-bearing boulders ANG is about 175°. Instead, mean PL and SL are quite VSE1 - The arrangement of the two tracks may be short: 28.3 and 57 cm, respectively. explained as a partial trackway of a bipedal stationary trackmaker or could just be the result of accidental preservation of footprints left by different individuals. DISCUSSION The preserved portion of the original surface is too small to ascertain it. No manus trace is observed on the boulder, The ichnotaxonomic assignment and identification but this could be due to the limited available surface and of the trackmakers of these very poorly to moderately the poor conditions of preservation. By its size, VSE1-1 well preserved footprints are tentative because their final can be compared to the ichnogenus Anchisauripus, but morphology may be biased by the following preservation it is less elongated and has a higher total divarication. factors: 1) the manus imprints are possibly not preserved However, as pointed out above, AII-IV as well as FL/FW because they were more faintly impressed than the pes may vary dependent on the conditions of the substrate. imprints and may have been wiped out more easily; 2) Plotting Te/FW and (FL-Te)/FW values of VSE1-1 in the the medial and lateral digit traces (digits I and V) may be diagram of Weems (1992, fig. 4), the footprint falls outside not preserved because originally they were less deeply the clusters identified in that diagram. impressed than digits II to IV (see King & Benton, Considering a generic bipedal dinosaur as trackmaker, 1996; Sarjeant, 1996). Extramorphological (substrate- its height at hip is estimated at 101.2 cm, while considering related) influences on the track shape are extremely a theropod as trackmaker (see below), its height at hip is important but often have not been considered adequately estimated at 99 cm. in the studies, resulting in misidentifications as well as ichnotaxonomic oversplitting. The determination of VSE2 - An assignment of those footprints to Anchisauripus is in agreement with their size and total digit divarication, but the relative slenderness (FL/FW) and the projection of digit III are similar to those of Eubrontes (Olsen et al., 1998). Plotting Te/FW and (FL- Te)/FW values of VSE2-1A in the diagram of Weems (1992, fig. 4), the footprint falls within the margin of a cluster including Anchisauripus minusculus Hitchcock, 1858, “Eubrontes giganteus” Hitchcock, 1836, E. tuberatus (Hitchcock, 1858), and Gigandipus caudatus Hitchcock, 1856. Values for digit length ratios III/II (1.36) and III/IV (0.91) in VSE2-1A plotted in the diagram of Farlow & Lockley (1993, fig. 2) fall between the plots of theropods (, Syntarsus, and Procompsognathus) and those of other early Mesozoic dinosaurs (Heterodontosaurus, Lufengosaurus, Plateosaurus, and Massospondylus). Considering a generic bipedal dinosaur as trackmaker, its height at hip is estimated at 98.90 cm, while considering a theropod as trackmaker (see below), its height at hip is Fig. 10 - Boulder AVG3. a) Photograph of footprint AVG3; b) estimated at 96.75 cm. If the tracks were produced by interpretative drawing. IV = trace of digit IV. Scale bar: 10 cm. the same foot, SL is 99 cm, SL/h is rather low (1-1.02, M. Marzola & F.M. Dalla Vecchia - Triassic dinosaur tracks from the Carnian Prealps 11

Fig. 11 - Boulder VPE1. a) Photograph of the trackway VPE1-1; b) interpretative drawing of VPE1-1; c) footprint VPE1-1B, photograph of the cast (left, light from the top left; right, light from the top right); d) interpretative drawing of VPE1-1B (based on the cast and mirrored). IV = trace of digit IV. Scale bar: 10 cm in a-c, 5 cm in d. indicative of slow walk) and consequently also the speed length ratios III/II (1.69) and III/IV (1.37) plotted in the is low (2.88 km/h, calculated for a theropod trackmaker). diagram of Farlow & Lockley (1993, fig. 2) fall far from VSE3 - This footprint is in the lower size-range the plotted dinosaurs, but closer to theropods than to the of Anchisauripus and has an elongated digit III like other early Mesozoic dinosaurs. Grallator, but FL/FW is much lower and AII-IV higher Considering a generic bipedal dinosaur as trackmaker, than in these two ichnotaxa. However, as pointed out its height at hip is estimated at 79.60 cm, while considering above, AII-IV and consequently also FL/FW may vary a theropod as trackmaker (see below), its height at hip is dependent on the physical properties of the substrate. estimated at 77.85 cm. Plotting Te/FW and (FL-Te)/FW values in the diagram of Weems (1992, fig. 4), the footprint falls outside all VSE4 - It is in the size-range of Anchisauripus, but clusters in the lower part of the diagram. Values for digit its poor preservation prevents any further comparison. 12 Bollettino della Società Paleontologica Italiana, 53 (1), 2014

Considering a generic bipedal dinosaur as trackmaker, its AVG2-2A is in the size-range of Anchisauripus, but height at hip is estimated at 101.2 cm, while considering it is slightly less elongated than footprints referred to a theropod as trackmaker (see below), its height at hip is that ichnogenus. Considering a generic bipedal dinosaur estimated at 99 cm. as trackmaker, its height at hip is estimated at 96.60 cm, VSE5 - If the actual morphology is that of the short while considering a theropod as trackmaker (see below), digit III option, this footprint is different from any other its height at hip is estimated at 94.50 cm. SL/h is 1.56/1.60 Triassic tridactyl footprints. In the case of the groove and V is 5.84/5.99 km/h. representing the actual digit III trace, size matches The high total divarication and low FL/FW of AVG2- Grallator, but AII-IV is too high for this ichnogenus as 3 are unlike those of the other tridactyl footprints in well as for Anchisauripus. However, AII-IV may vary the sample as well as the tridactyl ichnotaxa Grallator, dependent on the conditions of the substrate. Plotting Te/ Anchisauripus and Eubrontes. They are more similar FW and (FL-Te)/FW values in the diagram of Weems to those of Anomoepus, but there is no trace of the (1992, fig. 4), the footprint falls outside all clusters in the manus associated and the state of preservation does not lower part of the diagram. Values for digit length ratios allow to observe the diagnostic features of this Jurassic III/II (1.63) and III/IV (1.51) plotted in the diagram of ichnogenus (Olsen & Rainforth, 2003). Considering the Farlow & Lockley (1993, fig. 2) fall far from the plotted maximum footprint length and a generic bipedal dinosaur dinosaurs, but closer to theropods than to the other early as trackmaker, its height at hip is estimated at 82.80 cm; Mesozoic dinosaurs, like VSE3, probably because the considering a theropod as the trackmaker (see below), its footprint does not reflect the actual proportions of the height at hip is estimated at 81 cm. digits. Considering the maximum footprint length and a If the length of the digit III trace of AVG2-4 reflects generic bipedal dinosaur as trackmaker, its height at hip is the anatomical length of the trackmaker’s digit, AVG2-4 estimated at 41.40 cm, while considering a theropod (see might be an incomplete chirotheriid track or an incomplete below), its height at hip is estimated at 40.5 cm. track of another pentadactyl or tetradactyl ichnogenus (but see Klein et al., 2006; Klein & Haubold, 2007). VSE6 - Size, broadness, total digital divarication and The isolated footprints AVG2-5 to 11 are in the relative shortness of digit III are within the limits of the size-range of Anchisauripus. The height at hip of the ichnogenus Eubrontes (Olsen et al., 1998). Plotting Te/ trackmakers is estimated at 92 cm if they were generic FW and (FL-Te)/FW values in the diagram of Weems bipedal dinosaurs, at 90 cm if theropods. (1992, fig. 4), the footprint falls within the cluster of “Eubrontes giganteus”, E. divaricatus Hitchcock, 1865, AVG3 - This footprint is positioned at the boundary E. approximatus Hitchcock, 1865, and E. platypus between the size-range of Eubrontes and Anchisauripus. Hitchcock, 1858. Its total digital divarication II-IV is in the range of both Values for digit length ratios III/II (2.13) and III/IV ichnotaxa, but its width is larger than that of Anchisauripus. (1.58) plotted in the diagram of Farlow & Lockley (1993, Plotting Te/FW and (FL-Te)/FW values in the diagram fig. 2) fall far from the plotted dinosaurs, probably because of Weems (1992, fig. 4), the footprint falls within the footprint does not reflect the actual proportions of the the cluster of Anchisauripus minusculus, “Eubrontes digits. giganteus”, E. tuberatus and Gigandipus caudatus. Values Considering a generic bipedal dinosaur as trackmaker, for digit length ratios III/II (1.69) and III/IV (1.04) plotted the height at hip is estimated at 118.20-146.50 cm (using in the diagram of Farlow & Lockley (1993, fig. 2) fall the morphometric ratios method of Thulborn, 1990 for close to the plotted values of the theropods. both small and large bipedal dinosaurs because the size Considering a generic bipedal dinosaur as trackmaker, boundary between the two groups is at FL = 25 cm). its height at hip is estimated at 115.5-143.1 cm (using Considering a theropod as trackmaker (see below), its the morphometric ratios method of Thulborn, 1990 for height at hip is estimated at 125.9-115.7 cm. both small and large bipedal dinosaurs because the size boundary between the two groups is at FL = 25 cm); AVG1 - All footprints are in the size range of Grallator. considering a theropod as the trackmaker (see below), its Considering a generic bipedal dinosaur as trackmaker, the height at hip is estimated at 113-123 cm. height at hip is estimated at 62.10, 59.80, and 62.10 cm for AVG1-2, AVG1-3 and AVG1-1, respectively; considering VPE1 - The tracks are in the size-range of Anchisauripus, a theropod as trackmaker (see below), the height at hip is but the relative broadness (FL/FW) of VPE1-1B, its total estimated at 60.75, 58.50 and 60.75 cm. divarication and the moderate projection of digit III are The gait was a slow walk according to SL/h (1.11/1.14 more similar to those of Eubrontes. and 1.09/1.11 for AVG1-2 and AVG1-3, respectively) and Plotting Te/FW and (FL-Te)/FW values in the diagram V was 2.65/2.71 km/h and 2.50/2.57 km/h for AVG1-2 of Weems (1992, fig. 4), the footprint falls in the lower part and AVG1-3, respectively. of the cluster of “Eubrontes giganteus”, E. divaricatus, E. approximatus and E. platypus. Values for digit length AVG2 - The poor state of preservation of AVG2-1 ratios III/II (1.12) and III/IV (1.65) plotted in the diagram prevents any comparisons with known tridactyl ichnotaxa; of Farlow & Lockley (1993, fig. 2) fall outside the diagram however, AVG2-1B is in the size-range of Anchisauripus. space; if the specimen is a right footprint (with III/II = Considering a generic bipedal dinosaur as trackmaker, its 1.65 and III/IV = 1.12) it would be close to the plotted height at hip is estimated at 82.80 cm, while considering values of the theropods. a theropod as trackmaker (see below), its height at hip is Considering a generic bipedal dinosaur as trackmaker, estimated at 81 cm. its height at hip is estimated at 93.40 cm; considering a M. Marzola & F.M. Dalla Vecchia - Triassic dinosaur tracks from the Carnian Prealps 13 theropod as the trackmaker (see below), its height at hip also considered by some authors (e.g., Gand & Demathieu, is estimated at 91.35 cm. It was moving very slowly (SL/h 2005). Atreipus from the Upper Triassic of Europe and is 0.61/0.62) and its speed was very low (V = 1.19/1.22 North America has been attributed to an ornithischian km/h); this contrasts with the high pace angulation (see dinosaur or a basal dinosauriform by Olsen & Baird Alexander, 1976; Demathieu, 1984). (1986), to the by Thulborn (1993), to the by Haubold (1986) and Weishampel (2006), to basal by Haubold & Klein (2000), and THE IDENTIFICATION OF to the Dinosauriformes in general by Irmis et al. (2007a) POSSIBLE TRACKMAKERS and Nesbitt et al. (2007). Atreipus is also interpreted as a probable dinosauriform ichnite by D’Orazi Porchetti et Most of the new tracks from the PNDF appear to al. (2008). As seen above, most of the tridactyl footprints have been left by functionally tridactyl, digitigrade and preserved on the boulders from the PNDF and described bipedal trackmakers. Small to medium-sized tridactyl herein are in the size range of Anchisauripus (Tab. 1) and footprints with slender, pointed digit traces and low total do not show an associated manus imprint. digital divarication, along trackways produced by bipeds Taking the skeletal reconstruction of were traditionally referred to theropod dinosaurs (e.g., ischigualastensis (see Paul, 2010, p. 69) as a model for a Haubold, 1971; Thulborn, 1990; Lockley, 1991). In the generalized dinosauromorph bipedal trackmaker and using post-Triassic record, the only alternative trackmakers for the hip height calculation model of Thulborn (1990, fig. those footprints are bipedal ornithischians (Thulborn, 8.4) referred to generic bipedal dinosaurs (Thulborn, 1990, 1990; Lockley, 1991). p. 251), the total body length of the producer of the largest However, the situation is much more complicated when footprint in our sample (VSE6, 25.7 cm long) would be in the Upper Triassic record is considered. Here we have to the range 4.42-5.48 m, while that of the smaller one (VSE5, deal with a high diversity of potential bipedal trackmakers: 9 cm long) would be 1.55 m. Trackmakers of the most these include dinosaurs such as basal saurischians, abundant footprints in our sample (the Anchisauripus-size basal theropods, basal ornithischians and possibly basal class) would have a total body length ranging between sauropodomorphs (see Carrano, 2000; Langer, 2003; 3.10 and 3.70 m (mean 3.53 m). Many Triassic bipedal Butler et al., 2007; Langer et al., 2010; Martinez et al., dinosaurs (e.g., mertii Casamiquela, 1967, 2011), non-dinosaurian dinosauromorphs (Padian, 1997; Eocursor parvus Butler, Smith & Norman, 2007, Langer et al., 2010; Piechowski & Dzik, 2010; Klein et lunensis Sereno, Forster, Rogers & Monetta, 1993, al., 2011), and even pseudosuchian archosaurs (Nesbitt Alwalkeria maleriensis [Chatterjee, 1987], Guaibasaurus & Norell, 2006; Nesbitt, 2007; Gauthier et al., 2011). canderlariensis Bonaparte, Ferigolo & Ribeiro, 1999, Furthermore, the systematic position of many Triassic pricei Colbert, 1970, murphi dinosaurs is debatable: for example, Herrerasaurus Martínez, Sereno, Alcober, Colombi, Renne, Montañez ischigualastensis Reig, 1963 was considered a basal & Currie, 2011, Langer, Abdala, theropod by Sereno et al. (1993), Sereno & Novas (1994), Richter & Benton, 1999, protos Martínez & Sereno (2007), Martinez et al. (2011) and Sues et al. Alcober, 2009, and Asylosaurus yalensis Galton, 2007) (2011), but a basal saurischian by Langer (2004), Langer have estimated body lengths ≤ 2 m (Paul, 2010; Martínez & Benton (2006), and Novas et al. (2011). et al., 2011). Also, silesaurids ( opolensis Another difficulty is the incomplete record of skeletons Dzik, 2003, baldwini Sullivan & Lucas, of potential bipedal trackmakers: usually, the autopodia of 1999, smalli Chatterjee, 1984, Late Triassic archosaurs are only fragmentarily preserved agudoensis Ferigolo & Langer, 2007 and Diodorus or completely missing, therefore, our knowledge about scytobrachion Kammerer, Nesbitt & Shubin, 2011) their anatomy and digit proportions is restricted (e.g., (Dzik, 2003; Langer et al., 2010) and the lagerpetonids Walker, 1964; Casamiquela, 1967; Romer, 1972a; Krebs, Dromomeron gregorii Irmis, Nesbitt, Padian, Smith, 1976; Chatterjee, 1984, 1987; Long & Murry, 1995; Hunt Turner, Woody & Downs, 2007b and D. romeri Nesbitt, et al., 1998; Langer et al., 1999; Sullivan & Lucas, 1999; Irmis, Parker, Smith, Turner & Rowe, 2009, which were Langer, 2004; Butler et al., 2007; Ferigolo & Langer, 2007; probably facultative bipeds, were ≤ 2 m in length. They Galton, 2007; Irmis et al., 2007a, b; Nesbitt, 2007, 2011; seem to be too small for most of the PNDF footprints. Nesbitt et al., 2009, 2010; Martínez & Alcober, 2009; The largest tridactyl footprints of the PNDF are in Ezcurra, 2010; Kammerer et al., 2011; Novas et al., 2011; the range of Herrerasaurus ischigualastensis (total body Sues et al., 2011). length 4.5 m; Paul, 2010), the bipedal pseudosuchian Tracks of the Grallator-Eubrontes type are usually Poposaurus gracilis Mehl, 1915 (total body assigned to theropod trackmakers (Olsen et al., 1998; Klein length about 5 m; see Schachner et al., 2011), and the & Lucas, 2010). Haubold & Klein (2000, 2002), Klein & theropod liliensterni von Huene, 1934 (total Haubold (2007), and Klein et al. (2011) refer the footprints body length 5.2 m; Paul, 2010). However, Herrerasaurus of the Grallator-Atreipus plexus to dinosauromorphs. ischigualastensis has a scarcely projecting digit III and a The are composed of the Lagerpetidae comparatively long digit I, whose impression should be and the Dinosauriformes, the latter including visible, at least in well-preserved footprints. Poposaurus admixtus Romer, 1972a, lilloensis (Romer, gracilis probably was also tetradactyl (see Schachner 1972b), elginensis von Huene, 1910, the et al., 2011). Liliensternus liliensterni has a scarcely , and the Dinosauria (Langer et al., 2013). A projecting digit III, but apparently had a reduced digit I dinosauromorph affinity of some footprints (Rowe & Gauthier, 1990). Most of the tridactyl footprints referred to “Anchisauripus” and “Coelurosaurichnus” is in the sample are in the size range of the herrerasaurid 14 Bollettino della Società Paleontologica Italiana, 53 (1), 2014

Chindesaurus bryansmalli Long & Murry, 1995 (total A short, quadrupedal trackway segment from the body length 2.4 m; Paul, 2010) and the basal theropod Upper Susaibes Creek locality (Dalla Vecchia & Mietto, Coelophysis bauri (Cope, 1887) (total body length up to 1998, fig. 11) might also be assigned to chirotheriids; 3 m; Paul, 2010) or close to it. Unfortunately, the pes of unfortunately, only the small (13 cm long) tetradactyl bryansmalli is unknown (Long & Murry, trace of the manus is well preserved, while the pes prints 1995). Coelophysis bauri has a digit III projecting far are misshapen. beyond digits II and IV and a short digit I that barely Finally, an apparently quadrupedal trackway with touched the ground (Colbert, 1989). Thus, at the present large tridactyl pes prints 32-40 cm long and much smaller state of knowledge, theropod dinosaurs are still the best manus traces (Dalla Vecchia & Mietto, 1998, fig. 8) was trackmaker candidates for tridactyl footprints described reported from Forcella delle Pregoiane (Claut) by Dalla here. Vecchia & Mietto (1998). However, those authors doubt about the real identity of these structures as footprints because they could not observe them directly. THE PNDF FOOTPRINTS WITHIN THE The Norian-Rhaetian ichno-associations worldwide LATE TRIASSIC ICHNOASSOCIATIONS are dominated by tridactyl tracks of the Grallator- Eubrontes type (Grallator including Anchisauripus) Previously reported footprints from the PNDF and chirotheriid tracks referred to Brachychirotherium included tridactyl and mesaxonic footprints within the (sensu stricto) (Gatesy et al., 1999; Klein & Haubold, Anchisauripus size class (sensu Olsen et al., 1998) (a 2007; Klein & Lucas, 2010; Niedzwiedzki, 2011). total of three short trackways and at least 10 isolated The PNDF assemblage is distinguished by the rarity tracks from Ciol della Fratta A, Ciol del Tramontin and or possible absence of chirotheriid footprints and by Upper Susaibes Creek localities; Dalla Vecchia & Mietto, the dominance of middle-sized (Anchisauripus size- 1998, figs 5-6 and 9-11) and two consecutive tridactyl class) tridactyl footprints. With one possible exception, footprints within the Eubrontes size class (Dalla Vecchia tetradactyl footprints like Tetrasauropus Ellenberger, & Mietto, 1998, fig. 2). Dalla Vecchia & Mietto (1998) 1970, Pseudotetrasauropus, Otozoum, and Evazoum that noted the similarity of a 18 cm long, single tetradactyl might be referred to basal sauropodomorphs, are absent. footprint (Dalla Vecchia & Mietto, 1998, fig. 6) from Ciol On the contrary, basal sauropodomorphs are the most della Fratta. A locality with the ichnospecies Sphingopus common dinosaurs in the Norian-Rhaetian terrestrial ferox Demathieu, 1966, which, however, is typical of the tetrapod associations of Europe based on skeletal remains Middle Triassic according to Klein & Haubold (2007). (Weishampel et al., 2004). Alternatively, this specimen could be a tridactyl footprint The other footprint-bearing localities of the Dolomia like the others present in the same surface, which is Principale in NE Italy have yielded small to large- casually associated with a close but distinct depression, sized tridactyl footprints mostly referred to theropods, or an incomplete chirotheriid pes imprint. trackways and some tetradactyl footprints attributed to A trackway with footprints made apparently by a basal sauropodomorphs, a trackway referred to a basal bipedal trackmaker was reported by Dalla Vecchia & ornithischian, and a single chirotheriid footprint (Mietto, Mietto (1998) from Scandoler Valley (Dalla Vecchia 1988, 1991; Dalla Vecchia & Mietto, 2000; Leonardi, & Mietto, 1998, figs 3-4); footprints are 18 cm long, 2000; Belvedere et al., 2008). apparently not tridactyl, with outer rotation (8°-28°) and A block at Mt Pelmetto locality (Belluno Dolomites, relatively low pace angulation (140°-160°). However, Belluno Province) preserves four trackways and some because of logistic problems (the footprint-bearing isolated tridactyl footprints belonging to the Grallator surface was vertical), those authors could not observe the size-class, which were referred to small theropods (Mietto, trackway directly and they described it from photographs. 1988). The same block preserves also two trackways A single 22-23 cm long track from the Upper assigned to a small basal sauropodomorph and to a small Susaibes Creek locality is apparently pentadactyl (Dalla basal ornithischian, respectively (Mietto, 1988; Leonardi, Vecchia & Mietto, 1998, fig. 10); Dalla Vecchia & 2000). Several small to large-sized tridactyl footprints Mietto (1998) and Dalla Vecchia (2006) noticed the and the trackway of a quadrupedal trackmaker composed resemblance with the ichnogenera Pseudotetrasauropus of subelliptical footprints were recorded in other blocks Ellenberger, 1972, Otozoum Hitchcock, 1847, and (Dalla Vecchia & Mietto, 2000). A “chirotheroid” Evazoum Nicosia & Loi, 2003. Those ichnotaxa are, footprint referred to Brachychirotherium sp. was found however, tetradactyl and considered extramorphological on the opposite side of the main block (Dalla Vecchia variants of Brachychirotherium Beurlen, 1950 by some & Mietto, 2000, p. 330). Two large tridactyl footprints authors (e.g., Klein et al., 2006; Klein & Haubold, 2007). referred to Eubrontes are reported from the Tre Cime di The track from the Upper Susaibes Creek locality, if Lavaredo (Belluno Dolomites, Belluno Province; Mietto, actually pentadactyl, is not a chirotheriid footprint because 1991; Leonardi, 2000) and a medium-sized tridactyl of the position and morphology of the digit V trace. footprint is reported from Puez (western Dolomites, A relatively wide quadrupedal trackway from Ciol Bolzano/Bozen Province; Leonardi, 2000). Finally, the della Fratta B locality with pes tracks 27-28 cm long “Strada delle Gallerie” site (Pasubio Massif, Vicenza (Dalla Vecchia & Mietto, 1998, fig. 7) could be a Province) yielded large (Eubrontes) and small (cf. chirotheriid trackway, but the poor preservation of the Grallator) tridactyl footprints referred to theropods and tracks does not allow a positive referral based on the tetradactyl footprints similar to Pseudotetrasauropus and identification of the diagnostic morphological features Evazoum assigned to basal sauropodomorphs (Belvedere of chirotheriid footprints. et al., 2008). M. Marzola & F.M. Dalla Vecchia - Triassic dinosaur tracks from the Carnian Prealps 15

As in the PNDF ichnoassociation, chirotheriid Mateus (Universidade Nova de Lisboa - GEAL Museu da Lourinhã, footprints and small (< 15 cm) tridactyl footprints seem Portugal) for a preliminary critical review of the manuscript and to be uncommon, being present essentially in the Mt to the reviewers Massimo Bernardi (MUSE Museo delle Scienze Pelmetto site. di Trento, Italy) and Hendrik Klein (Saurierwelt Paläontologisches Museum Neumarkt, Germany) for their useful comments that The sample of the PNDF is the largest described improved the original manuscript. sample of the Dolomia Principale ichnofauna and probably the most representative of its paleoichnological diversity. However, it must be kept on mind that the Dolomia REFERENCES Principale spans the uppermost Carnian to the Rhaetian, an interval of approximately 27 million years. Only the site Alexander R.McN. (1976). Estimates of speeds of dinosaurs. Nature, of Pasubio Massif has been dated on biostratigraphic bases 261: 129-130. (conodonts) to the latest middle Norian (Belvedere et al., Belvedere M., Avanzini M., Mietto P. & Rigo M. (2008). Norian dinosaur footprints from the “Strada delle Gallerie” (Monte 2008), while the stratigraphic position of the ichnofossils Pasubio, NE Italy). In Avanzini M. & Petti F. M. (eds), Italian from Mt Pelmetto at the base of the formation would Ichnology, Proceedings of the Ichnology session of Geoitalia 2007. suggest a latest Carnian age for them (Mietto, 1988). Studi Trentini di Scienze Naturali, Acta Geologica, 83: 267-275. Thus, it is possible - although not demonstrated - that Berra F., Delfrati L. & Ponton M. (2007). Dolomia Prinicipale. In the vertebrate paleoichnological record of the Dolomia Cita M.B., Abbate E., Aldighieri B., Balini M., Conti M.A., Principale averages different tetrapod faunas living in Falorni P., Germani D., Groppelli G., Manetti P. & Petti F.M. the area during different intervals of a wide time span, as - Carta Geologica d’Italia 1:50.000. Catalogo delle formazioni - suggested also by Belvedere et al. (2008). Unità tradizionali (1). Quaderni del Servizio Geologico d’Italia, serie III, 7: 63-72. Beurlen K. (1950). Neue Fährtenfunde aus der fränkischen Trias. Neues Jahrbuch für Geologie und Paläontologie - Monatshefte, CONCLUSIONS 1950: 308-320. Bonaparte J.F., Ferigolo J. & Ribeiro A.M. (1999). A new early The most common trackmakers roaming on the Late Late Triassic saurischian dinosaur from Triassic tidal flats of the Dolomia Principale in the PNDF state, . In Tomida Y., Rich T.H. & Vickers-Rich P. (eds), were bipeds with a functionally tridactyl pes and a total Proceedings of the Second Gondwanan Dinosaur Symposium, body length around 3.5 m, occasionally around 5 m. National Science Museum Monographs,15: 89-109. According to the limited record of skeletal autopodia Bosellini A. (1967). La tematica deposizionale della Dolomia of bipedal or facultative bipedal Triassic archosaurs, the principale (Dolomiti e Prealpi venete). Bollettino della Società Geologica Italiana, 86: 133-169. best candidate trackmakers for those footprints are basal Bosellini A. & Hardie L.A. (1988). Facies e cicli dolomitici della theropods. Norian-Rhaetian ichnoassociations worldwide Dolomia Principale delle Alpi Venete. Memorie della Società are characterised by the presence of tridactyl mesaxonic Geologica Italiana, 30: 245-266. tracks (Grallator-Eubrontes type), but also by chirotheriid Braga Gp., Carloni G.C., Colantoni P., Corsi M., Cremonini G., tracks, which appear to be infrequent in the whole PNDF Frascari F., Locatelli D., Monesi A., Pisa G., Sassi F.P., Selli sample. R., Vai G.B., Zirpoli G. (1971). Note illustrative della carta The vast majority of footprints preserved on the ten geologica d’Italia alla scala 1:100.000. Fogli 4c-13. Monte new footprint-bearing boulders described in this paper Cavallino-Ampezzo. 108 pp. Nuova Tecnica Grafica, Roma. are tridactyl mesaxonic and apparently impressed by Butler R.J., Smith R.M.H. & Norman D.B. (2007). A primitive ornithischian dinosaur from the Late Triassic of South Africa, digitigrade and bipedal trackmakers. Most of these and the early evolution and diversification of Ornithischia. footprints range 15-25 cm in length as the ichnogenus Proceedings of the Royal Society B, 274: 2041-2046. Anchisauripus according to Olsen et al. (1998), smaller Carrano M.T. (2000). Homoplasy and the evolution of dinosaur footprints are more scarce and only two specimens are locomotion. Paleobiology, 26: 489-512. slightly longer than 25 cm. Only a single track might be Carulli G.B. (ed.) (2006). Carta geologica del , a chirotheriid one. scala 1:150.000, Regione Autonoma Friuli Venezia Giulia, Furthermore, tracks potentially produced by basal Direzione Regionale Ambiente e Lavori Pubblici, Servizio sauropodomorphs, which were the most common Geologico Regionale. dinosaurs in the Norian-Rhaetian interval, are also rare, Carulli G.B., Cozzi A., Longo Salvador G., Pernancic E., Podda F. & Ponton M. (2000). Geologia delle Prealpi Carniche. as are tridactyl and tetradactyl footprints of small-sized Pubblicazioni del Museo Friulano di Storia Naturale, 44: 1-47 dinosauromorphs. + geological map at scale 1:50,000, Udine. Casamiquela R.M. (1967). Un nuevo dinosaurio ornitisquio triásico (Pisanosaurus mertii; Ornithopoda) de la Formación ACKNOWLEDGEMENTS Ischigualasto. Ameghiniana, 4: 47-64. Chatterjee S. (1984). A new ornithischian dinosaur from the Triassic This work is mostly the result of the Master thesis work of the of North America. Naturwissenschaften, 71: 630-631. corresponding author (MM), undertaken at the Università degli Chatterjee S. (1987). A new theropod dinosaur from India with Studi di Ferrara during the years 2010-2012. Tutor was Benedetto remarks on the Gondwana-Laurasia connection in the Late Sala, co-tutors Giuseppe Muscio and the other author of this paper Triassic. In McKenzie G.D. (ed.), Gondwana 6: Stratigraphy, (FMDV). We thank Mauro Caldana, collaborator of the PNDF and Sedimentology and . Geophysical Monographs, President of the Associazione Naturalistica Cordenonese, for the 41: 183-189. discovery of the boulders, sharing all the information in his possess, Colbert E.H. (1970). A saurischian dinosaur from the Triassic of the casting of some footprints, and guiding us to the fossil-bearing Brazil. American Museum Novitates, 2405: 1-39. localities. We are grateful to Giuseppe Muscio, Museo Friulano di Colbert E.H. (1989). The Triassic dinosaur Coelophysis. Bulletin Storia Naturale of Udine, for the collaboration. Thanks to Octávio of the Museum of North Arizona, 57: 1-160. 16 Bollettino della Società Paleontologica Italiana, 53 (1), 2014

Cope E.D. (1887). The dinosaurian Coelurus. American fill (Rhaetian, Upper Triassic) at Clifton in Bristol, southwest Naturalist, 21: 367-369. England. Revue de Paléobiologie, 26: 505-591. Dalla Vecchia F.M. (2002). Terrestrial in the Norian of Gand G. & Demathieu G. (2005). Les pistes dinosauroides du the Carnian Pre-Alps (Friuli, NE Italy) - Paleoenvironmental Trias moyen francais: interprétation et réévaluation de la implications. Memorie della Società Geologica Italiana, 57: nomenclature. Geobios, 38: 725-749. 101-106. Gatesy S.M., Middleton K.M., Jenkins F.A. & Shubin N.H. (1999). Dalla Vecchia F.M. (2006). The tetrapod fossil record from the Three-dimensional preservation of foot movements in Triassic Norian-Rhaetian of Friuli (northeastern Italy). In Harris J.D., theropod dinosaurs. Nature, 399: 141-143. Lucas S.G., Spielmann J.A., Lockley M.G., Milner A.R.C. & Gauthier J.A., Nesbitt S.J., Schachner E.R., Bever G.S. & Joyce Kirkland J.I. (eds), The Triassic-Jurassic terrestrial transition. W.G. (2011). The bipedal stem crocodilian Poposaurus gracilis: New Mexico Museum of Natural History & Science Bulletin, inferring function in and innovation in Archosaur 37: 432-444. locomotion. Bulletin of the Peabody Museum of Natural History, Dalla Vecchia F.M. (2008). The impact of dinosaur palaeoichnology 52: 107-126. in palaeoenvironmental and palaeogeographic reconstructions Haubold H. (1971). Handbuch der Paläoherpetologie. T.18. Ichnia - the case of the Periadriatic carbonate platforms. Oryctos, 8: Amphibiorum et Reptiliorum fossilium. 124 pp. G. Fischer 89-106. Verlag, Stuttgart. Dalla Vecchia F.M. & Mietto P. (1998). Impronte di rettili terrestri Haubold H. (1986). Archosaur footprints at the terrestrial Triassic- nella Dolomia Principale (Triassico Superiore) delle Prealpi Jurassic transition. In Padian K. (ed.), The beginning of the age Carniche (Pordenone, Friuli). Atti Ticinesi di Scienze della of dinosaurs, Cambridge University Press: 189-201. Terra, 7: 87-107. Haubold H. & Klein H. (2000). Die dinosauroiden Fährten Dalla Vecchia F.M. & Mietto P. (2000). L’icnosito del Monte Parachirotherium-Atreipus-Grallator aus dem unteren Pelmetto (Triassico superiore, Cadore, Italia). Riassunti delle Mittelkeuper (Obere Trias: Ladin, Karn, ?Nor) in Franken. comunicazioni orali e dei posters - 80° Riunione Estiva S.G.I., Hallesches Jahrbuch für Geowissenschaften B, 22: 59-85. Trieste 6-8 settembre 2000: 329-330. Haubold H. & Klein H. (2002). Chirotherien und Grallatoriden aus Demathieu G. (1966). Rhynchosauroides petri et Sphingopus ferox, der Unteren bis Oberen Trias Mitteleuropas und die Entstehung nouvelles empreintes de Reptiles de grès triasiques de la bordure der Dinosauria. Hallesches Jahrbuch für Geowissenschaften Nord-Est du Massif Central. Comptes Rendus de l’Académie B, 24: 1-22. des Sciences, Série D, 263: 483-486. Hitchcock, E. (1836). Ornithichnology - description of the foot Demathieu G. (1984). Une ichnofaune du Trias moyen du Bassin marks of , (Ornithichnites) on new Red Sandstone in de Lodéve (Hérault, France). Annales de Paléontologie, 70: Massachusetts. The American Journal of Science and Arts, 247-273. 29: 307-340. Diàz-Martínez I., Pérez-Lorente F., Canudo J.I. & Pereda- Hitchcock E. (1845). An attempt to name, classify, and describe Suberbiola X. (2009). Causas de la variabilidad en icnitas de the that made the fossil footmarks of New England. dinosaurios y su aplicación en icnotaxonomía, Actas de las IV Proceedings of the 6th Annual Meeting of the Association of Jornadas Internacionales sobre Paleontología de Dinosaurios American Geologists and Naturalists, 6: 23-25. y su Entorno, Salas de los Infantes, Burgos, Spain. Colectivo Hitchcock E. (1847). Description of two new of fossil Arqueológico-Paleontológico Salense: 207-220. footmarks found in Massachusetts and Connecticut, or, of the D’Orazi Porchetti S., Nicosia U., Mietto P., Petti F.M. & Avanzini animals that made them. The American Journal of Science and M. (2008). Atreipus-like footprints and their co-occurrence with Arts, series 2, 4: 46-57. Evazoum from the upper Carnian (Tuvalian) of Trentino-Alto Hitchcock E. (1848). An attempt to discriminate and describe the Adige. In Avanzini M. & Petti F. M. (eds), Italian Ichnology, animals that made the fossil footmarks of the United States, and Proceedings of the Ichnology session of Geoitalia 2007. Studi especially of New England. Memoirs of the American Academy Trentini di Scienze Naturali, Acta Geologica, 83: 277-287. of Arts and Sciences, 3: 129-256. Dzik J. (2003). A beaked herbivorous archosaur with dinosaur Hitchcock E. (1856). Description of a new and remarkable species affinities from the early Late Triassic of Poland. Journal of of fossil footmark, from the sandstone of Turner’s falls, in the Vertebrate Paleontology, 23: 556-574. Connecticut Valley. American Journal of Science, ser. 2, 21: Ellenberger P. (1970). Les niveaux paleontologiques de premiere 97-100. apparition des Mammiferes Primordiaux en Afrique du Sud Hitchcock E. (1858). Ichnology of New England. A report on et leur Ichnologie: Establissement de zones stratigraphiques the sandstone of the Connecticut Valley, especially its fossil detaillees dans le Stormberg du Lesotho, (Afrique du Sud) (Trias footmarks. 214 pp. William White, Boston. Superieur a Jurassique). In Haughton S.H. (ed.), Z.U.G.S., 2nd Hitchcock E. (1865). Supplement to the Ichnology of New England. Symposium on Gondwana Stratigraphy and Palaeontology, 96 pp. Wright and Potter, Boston. Pretoria, Council for Scientific and Industrial Research: 343-370. Huene F. von (1910). Ein primitiver Dinosaurier aus der mittleren Ellenberger P. (1972). Contribution à la classification des Pistes de Trias von Elgin. Geologie und Paläontologie, Abhandlungen, Vertébrés du Trias: Les types du Stormberg d’Afrique du Sud 8: 317-322. (I). Palaeovertebrata. 104 pp. Memoire Extraordinaire. Huene F. von (1934). Ein neuer Coelurosaurier in der thüringischen Ezcurra M.D. (2010). A new early dinosaur (: Trias. Paläontologische Zeitschrift, 16: 145-170. Sauropodomorpha) from the Late Triassic of Argentina: a Huene F. von (1941). Die Tetrapoden-Fährten im toskanischen reassessment of dinosaur origin and phylogeny. Journal of Verrucano und ihre Bedeutung. Neues Jarhrbuch für Systematic Palaeontology, 8: 371-425. Mineralogie, Geologie und Paläontologie Abteilung, 86: 1-34. Farlow J.O. & Lockley M.G. (1993). An osteometric approach to the Hunt A.P., Lucas S.G., Heckert A.B., Sullivan R.M. & Lockley identification of the makers of early Mesozoic tridactyl dinosaur M.G. (1998). Late Triassic dinosaurs from the western United footprints. In Lucas S.G. & Morales M. (eds), The Nonmarine States. Geobios, 31: 511-531. Triassic. New Mexico Museum of Natural History and Science Irmis R.B., Nesbitt S.J., Padian K., Smith N.D., Turner A.H., Woody Bulletin, 3: 123-131. D. & Downs A. (2007b). A Late Triassic Dinosauromorph Ferigolo J. & Langer M.C. (2007). A Late Triassic dinosauriform Assemblage from New Mexico and the Rise of Dinosaurs. from south Brazil and the origin of the ornithischian predentary Science, 317: 358-361. bone. Historical Biology, 19: 23-33. Irmis R.B., Parker W.G., Nesbitt S.J. & Liu J. (2007a). Early Galton P.M. (2007). Notes on the remains of archosaurian reptiles, ornithischian dinosaurs: the Triassic record. Historical Biology, mostly basal sauropodomorph dinosaurs, from the 1834 fissure 19: 3-22. M. Marzola & F.M. Dalla Vecchia - Triassic dinosaur tracks from the Carnian Prealps 17

Kammerer C.F., Nesbitt S.J. & Shubin N.H. (2011). The first Manning P.L. (2004). A new approach to the anlysis and interpretation silesaurid dinosauriform from the Late Triassic of Morocco. of tracks: examples from the dinosauria. In McIlroy D. (ed.), Acta Palaeontologica Polonica, 57: 277-284. The Application of Ichnology to the Palaeoenvironmental and King M.J. & Benton M.J. (1996). Dinosaurs in the Early and Mid- Stratigraphic Analysis. Geological Society, London, Special Triassic? - The footprints evidence from Britain. Palaeogeography, Publications, 228: 93-123. Palaeoclimatology, Palaeoecology, 122: 213-225. Martínez R.N. & Alcober O.A. (2009). A basal sauropodomorph Klein H. & Haubold H. (2007). Archosaur footprints - potential (Dinosauria: Saurischia) from the for biochronology of Triassic continental sequences. In Lucas (Triassic, Carnian) and the early evolution of Sauropodomorpha. S.G. & Spielmann J.A. (eds), The Global Triassic. New Mexico PLoS ONE, 4: 1-12, e4397. Museum of Natural History & Science Bulletin, 41: 120-130. Martínez R.N., Sereno P.C., Alcober O.A., Colombi C.E., Renne Klein H. & Lucas S.G. (2010). Tetrapod footprints - their use in P.R., Montañez I.P. & Currie B.S. (2011). A Basal Dinosaur biostratigraphy and biochronology of the Triassic. Geological from the Dawn of the Dinosaur Era in Southwestern Pangaea. Society, London, Special Publications, 334: 419-446. Science, 331: 206-210. Klein H., Lucas S.G. & Haubold H. (2006). Tetrapod track Mehl M.G. (1915). Poposaurus gracilis, a new from the assemblage of the Redonda Formation (Upper Triassic, Triassic of Wyoming. Journal of Geology, 23: 516-522. Chinle Group) in east-central New Mexico - re-evaluation of Mietto P. (1988). Piste di dinosauri nella Dolomia Principale ichnofaunal diversity from studies of new material. In Harris (Triassico superiore) del M. Pelmetto (Cadore). Memorie della J.D., Lucas S.G., Spielmann J.A., Lockley M.G., Milner A.R.C. Società Geologica Italiana, 30: 307-310. & Kirkland J.I. (eds), The Triassic-Jurassic terrestrial transition. Mietto P. (1991). Impronte di dinosauri nel Triassico superiore New Mexico Museum of Natural History and Science Bulletin, delle Dolomiti. In Muscio G. (ed.), Dinosaurs. Il mondo dei 37: 241-250. dinosauri, Kaleidos: 83-87. Klein H., Voigt S., Saber H., Schneider J.W., Hminna A., Fischer J., Neri C., Gianolla P., Furlanis S., Caputo R. & Bosellini A. (2007). Lagnaoui A. & Brosig A. (2011). First occurrence of a Middle Note Illustrative della Carta Geologica d’Italia alla scala Triassic tetrapod ichnofauna from the Argana Basin (Western 1:50.000, Foglio 029 Cortina d’Ampezzo. APAT - Dipartimento High Atlas, Morocco). Palaeogeography, Palaeoclimatology, Difesa del Suolo-Servizio Geologico d’Italia, Roma. Palaeoecology, 307: 218-231. Nesbitt S.J. (2007). The anatomy of Effigia okeeffeae (Archosauria, Krebs B. (1976). . In Charig J., Krebs B., Sues Suchia), theropod-like convergence, and the distribution of H.-D. & Westphal F. (eds), . Handbuch der related taxa. Bulletin of the American Museum of Natural Paläoherpetologie, 13: 40-98. History, 302: 1-84. Langer M.C. (2003). The sacral and pelvic anatomy of the stem- Nesbitt S.J. (2011). The early evolution of archosaurs: relationships sauropodomorph Saturnalia tupiniquim (Late Triassic, Brazil). and the origin of major . Bulletin of the American Museum Paleobios, 23: 1-40. of Natural History, 352: 1-292. Langer M.C. (2004). Basal Saurischia. In Weishampel D.B., Dodson Nesbitt S.J., Irmis R.B. & Parker W.G. (2007). A critical re- P. & Osmólska H. (eds), The Dinosauria (2nd ed.). University of evaluation of the Late Triassic dinosaur taxa of North America. California Press: 25-46. Journal of Systematic Palaeontology, 5: 209-243. Langer M.C., Abdala F., Richter M. & Benton M.J. (1999). A Nesbitt S.J., Irmis R.B., Parker W.G., Smith N.D., Turner A.H. & sauropodomorph dinosaur from the Upper Triassic (Carnian) of Rowe T. (2009). Hind limb osteology and distribution of basal southern Brazil. Comptes Rendus de l’Academie des Sciences, dinosauromorphs from the Late Triassic of North America. Paris: Sciences de la Terre et des planètes, 329: 511-517. Journal of Vertebrate Paleontology, 29: 498-516. Langer M.C. & Benton M.J. (2006). Early dinosaurs: a phylogenetic Nesbitt S.J. & Norell M.A. (2006). Extreme convergence in the study. Journal of Systematic Palaeontology, 4: 309-358. body plans of an early suchian (Archosauria) and ornithomimid Langer M.C., Ezcurra M.D., Bittencourt J.S. & Nova F.E. (2010). dinosaurs (Theropoda). Proceedings of the Royal Society of The origin and early evolution of dinosaurs. Biological Reviews, London, Series B, Biological Sciences, 273: 1045-1048. 85: 55-110. Nesbitt S.J., Sidor C.A., Irmis R.B., Angielczyk K.D., Smith Langer M.C., Nesbitt S.J., Bittencourt J.S. & Irmis R.B. (2013). R.M.H. & Tsuji L.A. (2010). Ecologically distinct dinosaurian Non-dinosaurian Dinosauromorpha. Geological Society, sister group shows early diversification of Ornithodira.Nature , London, Special Publications, 379: 157-186. 464: 95-98. Leonardi G. (2000). I dinosauri d’Italia e delle aree adiacenti. In Nicosia U. & Loi M. (2003). Triassic footprints from Lerici (La Leonardi G. & Mietto P. (eds), Dinosauri in Italia - Le orme Spezia, northern Italy). Ichnos, 10: 127-140. giurassiche dei Lavini di Marco (Trentino) e gli altri resti fossili Niedzwiedzki G. (2011). A Late Triassic dinosaur-dominated italiani. Accademia Editoriale, Pisa-Roma: 275-295. ichnofauna from the Tomanová Formation of the Tatra Leonardi G. & Lockley M.G. (1995). A proposal to abandon the Mountains, Central Europe. Acta Palaeontologica Polonica, ichnogenus Coelurosaurichnus von Huene, 1941, a junior 56: 291-300. synonym of Grallator E. Hitchcock, 1858. Journal of Vertebrate Novas F.E., Ezcurra M.D., Chatterjee S. & Kutty T.S. (2011). Paleontology, 15: 40 (A). New dinosaur species from the Upper Triassic Upper Maleri Lockley M.G. (1991). Tracking dinosaurs: A new look at an ancient and Lower Dharmaram formations of central India. Earth and world. 238 pp. Cambridge University Press, Cambridge. Environmental Science Transactions of the Royal Society of Lockley M.G. & Gierliński G.D. (2006). Diverse vertebrate Edinburgh, 101: 333-349. ichnofaunas containing Anomoepus and other unusual trace fossils Olsen P.E. & Baird D. (1986). The ichnogenus Atreipus and its from the Lower Jurassic of the western United States: implications significance for Triassic biostratigraphy. In Padian K. (ed.), for paleoecology palichnostratigraphy. In Harris J.D., Lucas S.G., The Beginning of the Age of Dinosaurs, Cambridge University Spielmann J.A., Lockley M.G., Milner A.R.C. & Kirkland J.I. Press: 61-87. (eds), The Triassic-Jurassic terrestrial transition. New Mexico Olsen P.E. & Rainforth E.C. (2003). The Early Jurassic ornithischian Museum of Natural History and Science Bulletin, 37: 176-191. dinosaurian ichnogenus Anomoepus. In Le Tourneau P.M. & Long R.A. & Murry P.A. (1995). Late Triassic (Carnian and Norian) Olsen P.E. (eds), The Great Rift Valleys of Pangea in Eastern Tetrapods from the Southwestern United States. New Mexico North America. Sedimentology, Stratigraphy, and Paleontology, Museum of Natural History and Science Bulletin, 4: 1-254. 2, Columbia University Press: 314-367. Lull R.S. (1904). Fossil footprints of the Jura-Trias of North Olsen P.E., Smith J.B. & McDonald N.G. (1998). Type material America. Memoirs of the Boston Society of Natural History, of the type species of the classic theropod footprint genera 5: 461-557. Eubrontes, Anchisauripus, and Grallator (Early Jurassic, 18 Bollettino della Società Paleontologica Italiana, 53 (1), 2014

Hartford and Deerfield Basins, Connecticut and Massachusetts, Sues H-D., Nesbitt S.J., Berman D.S. & Henrici A.C. (2011). A USA). Journal of Vertebrate Paleontology, 18: 586-601. late-surviving basal theropod dinosaur from the latest Triassic Padian K. (1997). Bipedality. In Currie P.J. & Padian K. (eds), of North America. Proceedings of the Royal Society B, 278: Encyclopedia of Dinosaurs. Academic Press: 175-179. 3459-3464. Paul G. (2010). The Princeton Guide to Dinosaurs. 320 pp. Princeton Sullivan R.M & Lucas S.G. (1999). Eucoelophysis baldwini, a new University Press, Princeton & Oxford. theropod dinosaur from the Upper Triassic of New Mexico, Piechowski R. & Dzik J. (2010). The axial skeleton of Silesaurus and the status of the original types of Coelophysis. Journal of opolensis. Journal of Vertebrate Paleontology, 30: 1127-1141. Vertebrate Paleontology, 19: 81-90. Pittman J.G. (1989). Stratigraphy, lithology, depositional Thulborn R.A. (1993). A tale of three fingers: ichnological evidence environment, and track type of dinosaur track-bearing beds revealing the homologies of manual digits in theropod dinosaurs. of the Gulf Coastal Plain. In Gillette D.D. & Lockley M.G. In Lucas S.G. & Morales M. (eds), The Nonmarine Triassic. (eds), Dinosaur tracks and traces. Cambridge University Press: New Mexico Museum of Natural History and Science Bulletin, 135-153. 3: 461-463. Reig O.A. (1963). La presencia de dinosaurios saurisquios en Thulborn T. (1990). Dinosaur tracks. 410 pp. Chapman & Hall, los” Estratos de Ischigualasto”(Mesotriásico Superior) de las London, New York, Melbourne, Tokyo, Madras. provincias de San Juan y La Rioja (República Argentina). Upchurch P., Barrett P.M. & Galton P.M. (2007). A phylogenetic Ameghiniana, 3: 3-20. analysis of basal sauropodomorph relationships: Implications Romer A.S. (1972a). The Chañares (Argentina) Triassic reptile for the origin of sauropod dinosaurs, Special Papers in fauna. XIV. Lewisuchus admixtus, gen. et sp. nov., a further Palaeontology, 77: 57-90. thecodont from the Chañares beds. Breviora, 390: 1-13. Walker A.D. (1964). Triassic reptiles from the Elgin area Romer A.S. (1972b). The Chañares (Argentina) Triassic reptile Ornithosuchus and the origin of Carnosaurs. Philosophical fauna. XV. Further remains of the thecodonts and Transactions of the Royal Society of London, 744: 53-134. . Breviora, 394: 1-7. Weems R.E. (1992). A re-evaluation of the of Newark Rowe T. & Gauthier J. (1990). Ceratosauria. In Weishampel D.B., Supergroup saurischian dinosaur tracks, using extensive Dodson P. & Osmólska H. (eds), The Dinosauria, University statistical data from a recently exposed tracksite near Culpeper, of California Press: 151-168. Virginia. In Proceedings of the 26th Forum on the Geology of Safran J. & Rainforth E.C. (2004). Distinguishing the tridactyl Industrial Minerals - 14-18 May 1990, Virginia Division of dinosaurian ichnogenera Atreipus and Grallator: where are Mineral Resources Publication, 119: 113-127. the latest Triassic ornithischia in the Newark Supergroup? Weishampel D.B. (2006). Another look at the dinosaurs of the East Geological Society of America. Abstracts with Programs, 36: 96. Coast of North America. Actas III Jornadas Internacionales Sarjeant W.A.S. (1996). A re-appraisal of some supposed dinosaur sobre Paleontología de Dinosaurios y su Entorno, Salas de los footprints from the Triassic of the English Midlands. Mercian Infantes, Burgos, Spain. Colectivo Arqueológico-Paleontológico Geologist, 14: 22-30. Salense: 129-168. Schachner E.R., Manning P.L. & Dodson P. (2011). Pelvic and Weishampel D.B., Barrett P.M., Coria R.A., Le Loeuff J., Xing hind limb myology of the basal archosaur Poposaurus gracilis X., Xijin Z., Sahni A., Gomani E.M.P. & Noto C.R. (2004). (Archosauria: Poposauroidea). Journal of Morphology, 272: Dinosaur distribution. In Weishampel D.B., Dodson P. & 1464-1491. Osmólska H. (eds), The Dinosauria (2nd ed.). University of Sereno P.C. (2007). The phylogenetic relationships of early California Press: 517-606. dinosaurs: a comparative report. Historical Biology, 19: 145- 155. Sereno P.C., Forster C.A., Rogers R.R. & Monetta A.M. (1993). Primitive dinosaur skeleton from Argentina and the early evolution of Dinosauria. Nature, 361: 64-66. Manuscript received 12 March 2013 Sereno P.C. & Novas F. E. (1994). The skull and neck of the Revised manuscript accepted 10 December 2013 basal theropod Herrerasaurus ischigualastensis. Journal of Published online 19 February 2014 Vertebrate Paleontology, 13: 451-476. Editor Fabio Massimo Petti