New evidence of lacertiform tracks from the Middle-? Late Jurassic of Msemrir (Central High Atlas, Morocco): Palaeobiogeographical and palaeocoecological implications

This paper presents an ichnotaxonomic analysis of a slab with 12 tracks (pes and manus) preserved as natural casts (concave hyporelief) in sandstone slab from the Middle-Late Jurassic Guettioua Formation in the Mesmrir syncline (Central High Atlas, Morocco). Although most tracks are moderately preserved, one well-preserved and complete manus imprint regarded as pentadactyl, ectaxonic, highly asymmetrical, and plantigrade. Digit IV is the longest, while digits I and II are nearly equal and slightly shorter than digits III and IV (IV > III > I = II). The general morphology suggests a lacertoid-type track, comparable to those of a modern lizard. This specimen represents the third worldwide occurrence of Jurassic lacertoid tracks, and the first record in Gondwana. Palaeobiogeographically, the discovery confirms the presence of lacertoids along the southern margin of the Tethys and enriches our knowledge of their distribution across Gondwana during the Middle-Late Jurassic, a period that is still poorly documented in this aspect. Given the abundance and diversity of previously published tetrapod footprints, as well as the new traces described herein from the Guettioua Formation (Mesmerir syncline), this formation possibly contains traces of yet unknown Jurassic vertebrates. systematic fossil prospecting in this region is therefore strongly recommended.