Cranial morphology of Javanese Homo erectus: New evidence for continuous evolution, specialization, and terminal extinction

Global and local perspectives on cranial shape variation in Indonesian <i>Homo erectus</i>

“…Yet, the very young date reported by Yokoyama et al (2008) may reflect more recent hydrological activity unrelated to the actual deposition of these fossils (Indriati et al, 2011). Deposits spanning the Pleistocene are found in the area of the Sm 1 findspot (Kaifu et al, 2008). Sm 3 and 4 were found at the bottom of the Solo River in the same location, which was 4 km from the Sm 1 site.…”

“…The Sambungmacan calvaria (Sm 1, 3 and 4) are often grouped with the Ngandong fossils Baab, 2016b), but the former were all found by local inhabitants rather than during controlled excavations and may not be contemporaneous with each other or with the Ngandong fossils (Kaifu et al, 2008). Yokoyama et al (2008) found similar dates for two Ngandong (Ng 1 and Ng 7) and one Sambungmacan (Sm 1) fossil, suggesting that this assumption may be correct for at least some of the specimens.…”

“…In particular, recent analyses of 2D linear dimensions and non-metric features supported a linear transition from Sangiran/Trinil through Sambungmacan/Ngawi and onto Ngandong (Baba et al, 2003;Kaifu et al, 2006Kaifu et al, , 2008Kaifu et al, , 2015, a view also embraced by Wolpoff (1999). This conclusion was based on observations that geochronologically younger Sangiran fossils were more similar to later Indonesian fossils than were older ones, and that both Ngawi and the three Sambungmacan specimens displayed intermediate morphologies between Sangiran/Trinil and Ngandong.…”

“…More recent work that has focused on the cranial morphology of the Asian H. erectus fossil record includes evaluations of the metric and non-metric diversity of Asian or specifically the Indonesian fossil record Kaifu et al, 2008), cranial shape variation in the Asian fossils (Baab, 2010;Zeitoun et al, 2010), and analyses focused on the affinities of particular fossils (Delson et al, 2001;Widianto et al, 2001;Widianto and Zeitoun, 2003;Durband, 2006;Kaifu et al, 2006Kaifu et al, , 2015Indriati and Antón, 2010). It was demonstrated that Asian, along with numerous African and Georgian fossils assigned to H. erectus, were distinct from or displayed minimal overlap with other archaic Homo species on the basis of threedimensional (3D) neurocranial shape (Zeitoun et al, 2010;Baab, 2016b).…”

“…There is substantial variation within this sample that spans three continents and more than a million years of evolutionary change. Some of this variation is attributable to diachronic change (Wolpoff et al, 1994;Antón, 2003;Kaifu et al, 2005Kaifu et al, , 2008, and to geography (perhaps related to genetic drift or local adaptation) Kidder and Durband, 2004;Durband, 2006;Baab, 2010), but is also influenced by cranial size (Santa Luca, 1980;Antón et al, 2007;Baab, 2008b;Kaifu et al, 2008). Some studies have found that the Zhoukoudian hominins are particularly distinct in their craniometric dimensions Kidder and Durband, 2004), while others have indicated that the Ngandong/Sambungmacan/Ngawi series of calvaria are at least as distinct (Baab, 2010;Zeitoun et al, 2010).…”