Cite any non-quoted material obtained here as follows:

Calvert, A., K. Flammer, A. Hayes, C. Ibarra, T. Lin, D. Lowen, M. Pevey,M. Thompson, S. Vivelo, B. Wheelis, & H. Gilbert. 2024. Species naming and current status of Australopithecus sediba. Accessed from the Human Fossil Record Database at fossilized.org on September 16, 2024 .

 Australopithecus sediba

Synonyms: Australopithecus africanus

Australopithecus sediba would be assigned to Australopithecus africanus using the Fossilized.org alpha taxonomy

Original diagnosis:"Au. sediba can be distinguished from other species of Australopithecus by a combination of characters presented in Table 1; comparative cranial measures are presented in Table 2. A number of derived characters separate Au. sediba from the older chronospecies Au. anamensis and Au. afarensis. Au. sediba exhibits neither the extreme megadontia, extensive cranial cresting, nor facial prognathism of Au. garhi. The suite of derived features characterizing Au. aethiopicus, Au. boisei, and Au. robustus, in particular the pronounced cranial muscle markings, derived facial morphology, mandibular corpus robusticity, and postcanine megadontia, are absent in Au. sediba. The closest morphological comparison for Au. sediba is Au. africanus, as these taxa share numerous similarities in the cranial vault, facial skeleton, mandible, and teeth (Table 1). Nevertheless, Au. sediba can be readily differentiated from Au. africanus on both craniodental and postcranial evidence.Among the more notable differences, we observe that although the cranium is small, the vault is relatively transversely expanded with vertically oriented parietal walls and widely spaced temporal lines; the face lacks the pronounced, flaring zygomatics of Au. africanus; the arrangement of the supraorbital torus, nasoalveolar region, infraorbital region, and zygomatics result in a derived facial mask; the mandibular symphysis is vertically oriented with a slight bony chin and a weak post-incisive planum; and the teeth are differentiated by the weakly defined buccal grooves of the maxillary premolars, the weakly developed median lingual ridge of the mandibular canine, and the small absolute size of the postcanine dentition. These exact differences also align Au. sediba with the genus Homo (seeSOMtext S2 for hypodigms used in this study). However, we consider Au. Sediba to be more appropriately positioned within Australopithecus, based on the following craniodental features: small cranial capacity, pronounced glabelar region, patent premaxillary suture, moderate canine jugum with canine fossa, small anterior nasal spine, steeply inclined zygomaticoalveolar crest, high masseter origin, moderate development of the mesial marginal ridge of the maxillary central incisor, and relatively closely spaced premolar and molar cusps. Postcranially, Au. sediba is similar to other australopiths in its small body size, its relatively long upper limbs with large joint surfaces, and the retention of apparently primitive characteristics in the upper and lower limbs (table S2). Au. sediba differs from other australopiths, but shares with Homo a number of derived features of the os coxa, including increased buttressing of the ilium and expansion of its posterior portion, relative reduction in the distance between the sacroiliac and hip joints, and reduction of distance from the acetabulum to the ischial tuberosity. These synapomorphies with Homo anticipate the reorganization of the pelvis and lower limb in H. erectus and possibly the emergence of more energetically efficient walking and running in that taxon (17). As with the associated cranial remains, the postcranium of Au. sediba is defined not by the presence of autapomorphic features but by a unique combination of primitive and derived traits."