Begat Arnaud, Kriwet Jürgen, Gelfo Javier N, Cavalli Soledad Gouiric, Schultz Julia A, Martin Thomas
Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Josef-Holaubek-Platz 2, Vienna, 1090, Austria.
Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, Vienna, 1030, Austria.
J Vertebr Paleontol. 2023 Feb 9;42(2). doi: 10.1080/02724634.2022.2162411. eCollection 2022 Aug 31.
A new extinct sclerorhynchoid sawfish, sp. nov., is presented here based on abundant isolated teeth and some dermal denticles, which were recovered from the Mata Amarilla Formation, belonging to the lower Upper Cretaceous of the Santa Cruz Province in the Austral Basin of Patagonia, Argentina. This new species is the first occurrence in the southern hemisphere, which so far only has been reported from northern hemisphere deposits (Europe, North Africa, and North America). The presence of sp. nov. in these southern high-latitude deposits of Patagonia, Argentina, extends the geographic range of considerably southwards. This distribution pattern in the "middle" Cretaceous seems to correlate with the South Atlantic opening at the end of the Albian. The presence of lateral cephalic dermal denticles and the simultaneous absence of rostral denticles in the abundant fossil material support the view that did not develop such rostral structures. A reinvestigation of all known species assigned to reveals that is a junior synonym of belongs to belongs to , and represents an unidentifiable species (? sp.). The stratigraphic distribution demonstrates that might have originated in the Albian in south-western Europe and subsequently dispersed to obtain its widest distribution during the Cenomanian. In the Coniacian, a steep diversity decline is recognizable with a subsequent distribution shift from Europe to North America.
本文基于大量孤立的牙齿和一些皮齿，描述了一种新的已灭绝的硬吻鲼类锯鳐，新物种。这些化石采自阿根廷巴塔哥尼亚南部盆地圣克鲁斯省上白垩统下部的马塔阿马里拉组。该新物种是在南半球首次出现，此前仅在北半球的沉积物（欧洲、北非和北美）中有报道。阿根廷巴塔哥尼亚这些高纬度南部沉积物中该新物种的出现，将其地理分布范围大幅向南扩展。这种在白垩纪“中期”的分布模式似乎与阿尔比阶末期南大西洋的张开有关。大量化石材料中存在头部侧面的皮齿而同时没有吻部皮齿，这支持了该物种没有发育出这种吻部结构的观点。对所有已知归入该属的物种进行重新研究表明，该物种是 的次异名， 属于 ， 属于 ，而 代表一个无法鉴定的物种（？种）。地层分布表明，该物种可能起源于欧洲西南部的阿尔比阶，随后扩散并在森诺曼阶达到最广泛的分布。在科尼亚克阶，其多样性急剧下降，随后分布范围从欧洲转移到北美。
