Raventós-Izard Georgina, Monclús-Gonzalo Oriol, Moyà-Solà Salvador, Alba David M, Arias-Martorell Julia
Institut Català de Paleontologia Miquel Crusafont (ICP-CERCA), Universitat Autònoma de Barcelona, Edifici ICTA-ICP, c/ Columnes s/n, Campus de la UAB, 08193 Cerdanyola del Vallès, Barcelona, Spain.
Institut Català de Paleontologia Miquel Crusafont (ICP-CERCA), Universitat Autònoma de Barcelona, Edifici ICTA-ICP, c/ Columnes s/n, Campus de la UAB, 08193 Cerdanyola del Vallès, Barcelona, Spain.
J Hum Evol. 2025 May;202:103663. doi: 10.1016/j.jhevol.2025.103663. Epub 2025 Mar 17.
Pliobates cataloniae is a small-bodied crouzeliid pliopithecoid from the Miocene (∼11.6 Ma) of Abocador de Can Mata (ACM; Vallès-Penedès Basin, NE Iberian Peninsula). It exhibits a mosaic of primitive (stem catarrhine) and derived (modern hominoid-like) postcranial features. The holotype partial skeleton, from locality ACM/C8-A4, includes an almost complete ulna-a bone that plays a critical role in forearm flexion-extension and pronation-supination. Here, we use landmark-based three-dimensional geometric morphometrics to evaluate the closest morphometric affinities of the Pliobates ulna and explore its implications for the locomotor repertoire of this taxon. The comparative sample includes 156 specimens corresponding to 35 species from 20 anthropoid genera, three lorisid genera, and 10 fossil catarrhines. Our results indicate that the trochlear notch morphology of Pliobates resembles that of stem catarrhines and other nonhominoid primates. However, Pliobates differs from cercopithecoids (especially terrestrial taxa) in radial notch features related to enhanced pronation-supination capabilities, closely resembling the condition displayed by crown hominoids, Ateles, and Loris. In turn, the distal ulna of Pliobates does not overlap with any extant group and differs from the other fossils analyzed, most closely resembling that of hylobatids and lorisids. Pliobates probably had an extensive range of movement in the distal forearm, as indicated by the incipiently expanded semilunar ulnar head, the relatively short styloid process, the deep fovea, and the hooklike styloid process. This suggests that Pliobates would have frequently displayed nonstereotypical limb postures and slow locomotor behaviors. Overall, the ulnar morphology of Pliobates suggests that its locomotor repertoire may have combined cautious above-branch quadrupedalism and eclectic climbing with nonagile suspensory behaviors resembling those of Ateles.
加泰罗尼亚普氏猿是一种体型较小的克鲁泽利猴科阔鼻猴类，来自中新世（约1160万年前）的卡恩马塔阿博卡多尔（ACM；伊比利亚半岛东北部的瓦莱-彭内德斯盆地）。它展现出一系列原始（原猴亚目主干）和衍生（类似现代类人猿）的颅后特征。来自ACM/C8-A4地点的正模部分骨骼，包括一根几乎完整的尺骨——这根骨头在前臂屈伸和旋前-旋后中起着关键作用。在此，我们使用基于地标点的三维几何形态测量学来评估普氏猿尺骨最接近的形态测量亲缘关系，并探讨其对该分类单元运动方式的影响。比较样本包括156个标本，对应20个人猿总科属、3个懒猴科属和10个化石狭鼻猴类的35个物种。我们的结果表明，普氏猿的滑车切迹形态类似于原猴亚目主干和其他非类人猿灵长类动物。然而，普氏猿在与旋前-旋后能力增强相关的桡切迹特征方面与猕猴科动物（尤其是陆生类群）不同，与类人猿冠类、蜘蛛猴属和懒猴属所表现出的情况极为相似。反过来，普氏猿的尺骨远端与任何现存类群都不重叠，且与其他分析过的化石不同，最类似于长臂猿科和懒猴科。普氏猿的尺骨远端可能有广泛的活动范围，如半月形尺骨头开始扩张、茎突相对较短、凹窝较深以及茎突呈钩状所示。这表明普氏猿可能经常表现出非典型的肢体姿势和缓慢的运动行为。总体而言，普氏猿的尺骨形态表明其运动方式可能结合了谨慎的树上四足行走和不拘一格的攀爬，以及类似于蜘蛛猴属的不灵活的悬荡行为。
