The postcranial variability of Quaternary European rhinoceroses: the case study of <i>Stephanorhinus hundsheimensis</i> from the Middle Pleistocene site of Contrada Monticelli (Apulia, southern Italy)

Five rhinoceros species, mainly distinguishable through cranial, mandibular and dental morphology, were recognized during the Quaternary across Europe. The postcranial morphology of these taxa is quite variable, with strong superposition among species, especially between <i>Stephanorhinus etruscus</i> and <i>Stephanorhinus hundsheimensis</i>. Here, the complete sample including 25 postcranial bones from the early Middle Pleistocene site of Contrada Monticelli (Apulia, southern Italy) is described and compared through morphological and biometric analyses. A few bones, in addition to cranial and mandibular remains from this site, have been previously referred to <i>Stephanorhinus hundsheimensis</i>. We explored the morphological variability of <i>Stephanorhinus hundsheimensis</i> from Contrada Monticelli against the diagnostic characters described in the literature. The size variation of the Contrada Monticelli sample is also investigated, through a comparison with other Quaternary European rhinoceros samples. Our results indicate a wide morphological variability with several distinct characters and a strong morphological affinity between <i>Stephanorhinus etruscus</i> and <i>S. hundsheimensis</i>. Our results suggest that <i>Stephanorhinus hundsheimensis</i> from Contrada Monticelli is a species with a high degree of intraspecific variability, possibly a hybrid population or a population including two morphotypes of the same species.欧洲各地第四纪地层中已识别出五种犀牛物种，其分类鉴别主要依托颅骨、下颌骨与牙齿的形态学特征。该类群的颅后骨骼形态具有较高变异性，物种间形态重叠现象显著，尤以埃特鲁斯坎斯泰凡犀牛（Stephanorhinus etruscus）与洪斯海姆斯泰凡犀牛（Stephanorhinus hundsheimensis）为甚。本文针对意大利南部普利亚地区孔特拉达·蒙蒂切利（Contrada Monticelli）早中更新世遗址出土的25件完整颅后骨骼标本，通过形态学与生物测量学分析展开描述与对比研究。该遗址此前出土的部分骨骼（含颅骨与下颌骨标本）已被归入洪斯海姆斯泰凡犀牛（Stephanorhinus hundsheimensis）。本文基于文献中记载的鉴别特征，探究了孔特拉达·蒙蒂切利遗址洪斯海姆斯泰凡犀牛的形态变异性。同时，通过与欧洲其他第四纪犀牛标本集合的对比，本文还分析了该遗址标本群的尺寸变异情况。研究结果显示，该类群具有丰富的形态变异性与多项独特鉴别特征，且埃特鲁斯坎斯泰凡犀牛与洪斯海姆斯泰凡犀牛之间存在极强的形态亲缘关系。本研究结果表明，孔特拉达·蒙蒂切利遗址的洪斯海姆斯泰凡犀牛种群具有极高的种内变异性，可能为杂交种群，或是包含同一物种两种形态型的种群。