Re-evaluation ofChelichnus tazelwürmi,a non mammalian therapsid-grade track from the Upper Permian Arenaria di Val Gardena

Abstract

In this paper, a revision of tracks referred to as Chelichnus tazelwürmi is reported. The performed analysis, consisting of a holistic approach by means of a mainly morphological analysis, and a secondarily functional one, led to the proposal of a new ichnogenus, named as Contiichnus tazelwurmi. The three dimensional morphology of the tracks allows for the inference of a complex cycle of locomotion by the trackmakers. The tracks were formed in the main phases (i.e. touch-down, weight-bearing and kick-off ) by different axes of body load and transference, indicating that the whole fore autopod was involved in the cycle of locomotion and actively contacted the substrate, while for the hind autopod the functional prevalence was markedly centro-medial. Some track features suggest a therapsid-grade synapsid as potential trackmaker. However, the reconstructed autopodial structure does not correlate with known autopods from the Late Permian body fossil record. These observations stress the importance of tetrapod ichnology studies in improving knowledge in the field of vertebrate palaeontology. http://www.zoobank.org/urn:lsid:zoobank.org:pub:B4EB4D42-1A3B-48EC-B83F-6942F741AF30

Triassic pentadactyl tracks from the Los Menucos Group (Río Negro province, Patagonia Argentina): possible constraints on the autopodial posture of Gondwanan trackmakers

“…11 and 12). The fleshy pad behind the basipodials actively contacted the ground most likely during the touch-down and weight-bearing phase, as was already inferred from footprint depth of impression in other producers (e.g., Romano, Citton & Nicosia, 2016; Citton et al, 2017). Thus, from a functional standpoint, the autopod posture of the Pentasauropus trackmaker can be regarded as plantiportal ( sensu Michilsens et al, 2009) and it is considered to have been maintained during different gaits.…”

Tetrapod tracks in Permo–Triassic eolian beds of southern Brazil (Paraná Basin)

“…In addition, besides the four Chelichnus ichnospecies recognized by McKeever & Haubold (1996) (i.e., C. bucklandi, C. duncani, C. gigas and C. titan ), three others were also erected: C. incurvus Gand, Demathieu & Ballestra (1995) , C. lutevanus Ellenberger (1984) and C. tazelwürmi Ceoloni et al (1988) . The latter was recently re-evaluated ( Citton et al, 2017 ) and now it belongs to the ichnogenus Contiichnus , but the taxonomic meaning of the two former ichnospecies is still problematic.…”

First tetrapod footprints from the Permian of Sardinia and their palaeontological and stratigraphical significance

“…This method, whose practice is explained by several papers (e.g., Falkingham, ; Mallison & Wings, ; Petti et al, ), enables preservation and communication more objectively about ichnological data. Its adoption has greatly increased in recent times, becoming almost a standard taking advantage of a protocol for ichnological studies (Falkingham et al, ) and being used as support of different approaches related to ichnological analysis (e.g., Castanera et al, ; Citton, Carluccio, Nicolosi, & Nicosia, ; Citton, Nicolosi, Carluccio, & Nicosia, ; Citton, Nicosia, Nicolosi, Carluccio, & Romano, ; Citton et al, ; Citton, Romano, Salvador, & Avanzini, ; Lallensack, Sander, Knötschke, & Wings, ; McCrea et al, ; Romano & Citton, ). High‐resolution Digital Photogrammetry is based on Structure from Motion (SfM) (Ullman, ) and Multi View Stereo (MVS; Seitz, Curless, Diebel, Scharstein, & Szeliski, ) algorithms and produces high‐quality dense point clouds.…”

“…(mainly from the Orobic and Val Trompia basins), Tregiovo Fm. (Tregiovo Basin) and Athesian Volcanic Group (Monte Luco Basin; e.g., Avanzini, Neri, Nicosia, & Conti, ; Ceoloni, Conti, Mariotti, Mietto, & Nicosia, ; Marchetti, Ronchi, Santi, & Voigt, ; Marchetti, Ronchi, Santi, Schirolli, & Conti, ; Marchetti, Ronchi, Santi, & Voigt, ; Nicosia, Ronchi, & Santi, ; Nicosia, Ronchi, & Santi, ) and the extraordinarily diverse tetrapod footprint association from the Upper Permian Arenaria di Val Gardena (e.g., Bernardi et al, ; Ceoloni, Conti, Mariotti, & Nicosia, ; Citton et al, ; Citton, Carluccio, et al, ; Conti, Leonardi, Mariotti, & Nicosia, , , ; Leonardi, ; Leonardi & Nicosia, ; Leonardi, Conti, Leonardi, Mariotti, & Nicosia, ; Marchetti et al, ; Nicosia, Sacchi, & Spezzamonte, ; Valentini, Conti, & Mariotti, ; Valentini, Conti, & Nicosia, ; Valentini, Nicosia, & Conti, ).…”