New Neandertal wrist bones from El Sidrón, Spain (1994–2009)

Abstract

Twenty-nine carpal bones of Homo neanderthalensis have been recovered from the site of El Sidrón (Asturias, Spain) during excavations between 1994 and 2009, alongside ∼2500 other Neandertal skeletal elements dated to ∼49,000 years ago. All bones of the wrist are represented, including adult scaphoids (n = 6), lunates (n = 2), triquetra (n = 4), pisiforms (n = 2), trapezia (n = 2), trapezoids (n = 5), capitates (n = 5), and hamates (n = 2), as well as one fragmentary and possibly juvenile scaphoid. Several of these carpals appear to belong to the complete right wrist of a single individual. Here we provide qualitative and quantitative morphological descriptions of these carpals, within a comparative context of other European and Near Eastern Neandertals, early and recent Homo sapiens, and other fossil hominins, including Homo antecessor, Homo naledi, and australopiths. Overall, the El Sidrón carpals show characteristics that typically distinguish Neandertals from H. sapiens, such as a relatively flat first metacarpal facet on the trapezium and a more laterally oriented second metacarpal facet on the capitate. However, there are some distinctive features of the El Sidrón carpals compared with most other Neandertals. For example, the tubercle of the trapezium is small with limited projection, while the scaphoid tubercle and hamate hamulus are among the largest seen in other Neandertals. Furthermore, three of the six adult scaphoids show a distinctive os-centrale portion, while another is a bipartite scaphoid with a truncated tubercle. The high frequency of rare carpal morphologies supports other evidence of a close genetic relationship among the Neandertals found at El Sidrón.

Skeletal Anomalies in The Neandertal Family of El Sidrón (Spain) Support A Role of Inbreeding in Neandertal Extinction

“…Four of the seven scaphoids preserved at El Sidrón show morphological anomalies 63 . Three scaphoids (SDR-064, SD-258, SD-679b) retain a distinctive os centrale projection along the distoulnar border, while another scaphoid (SD-96) is bipartite with a truncated tubercle (Fig.…”

Three-Dimensional Comparative Study of Human Bipartite Scaphoids and the Os Centrale of the Wrist in Neandertals and Non-Human Anthropoid Primates

“…These remains have been dated to the late middle Paleolithic at about 49,000 years ago [ 26 ]. Two of the seven scaphoid bones from El Sidrón (SD-064 and SD-258) were examined because of the preservation of a distinct os centrale portion (small semi-circular projection approximatively midway along the distal border of the scaphoid body) [ 27 ] and because the morphology of SD-064 and SD-258 were preserved compared to the other specimens, which were broken with missing fragments (SD-679b, SD-110). These specimens show adult morphology.…”

Form, function and evolution of the human hand

“…Homo heidelbergensis (Lorenzo, 2012), Neandertals (e.g., Kivell, Churchill, et al, 2018;Kivell, Rosas, et al, 2018;Mersey et al, 2013;Musgrave, 1977;Niewoehner, 2006;Niewoehner et al, 1997;Trinkaus, 1982Trinkaus, , 1989Trinkaus & Walker, 2017) and fossil H. sapiens (e.g., Trinkaus & Jelínek, 1997;Trinkaus & Svoboda, 2006;Trinkaus et al, 2010).…”

“…Two partial skeletons from Malapa, South Africa-MH1, a late juvenile, likely male and MH2, an adult, likely female-date to 1.977 Ma (Berger et al, 2010;Pickering et al, 2011). While MH1 currently only preserves a third metacarpal missing its distal (unfused) epiphysis, a relatively complete right hand, plus a few bones from the left hand, is associated with a complete right upper limb in MH2 (Churchill et al, 2013;Churchill et al, 2018;Kivell et al, 2011; Tables 3-9; 22944J (Ward et al, 1999)] and modern humans (Kivell et al, 2011;Kivell, Churchill, et al, 2018;Kivell, Rosas, et al, 2018). The metacarpals, including the Mc1, are gracile, which, in combination with the (albeit poorly preserved) radial carpometacarpal region, suggests limited force production by the pollex.…”