Researchers María Martinón-Torres and José María Bermúdez, de Castro, from the National Center for Research on Human Evolution (CENIEH), are co-authors of a Tongzi hominid study, published in the magazine Journal of Human Evolution, which reveals that their teeth do not conform to the morphological pattern ofHomo erectus classic so could potentially represent the much sought after Denisovans.
The four teeth studied, found between 1972 and 1983 in Yanhui Cave in Tongzi, southern China, have a chronology between 240,000 and 172,000 years old, and were originally assigned toHomo erectus late or at aHomo sapiens archaic.
In this study, led by Song Xing from the Institute of Vertebrate Paleontology and Palaeoanthropology in Beijing (IVVP), in addition to standard morphological comparisons, the morphology of hominin teeth has been re-evaluated by geometric morphometric analysis and computed microtomography (micro- CT).
Tongzi's teeth were mainly compared with hominins from the same chronological period (Late Middle Pleistocene) and / or from the same geographic area (East Asia), although a wide range of hominins have been included in the comparative sample.
Usually, the results point to the existence of more than one human population in East Asia during this period: one that can be taxonomically classified as H. erectus (represented by fossils such as Zhoukoudian, Hexian and Yiyuan); Y a second that is characterized by the expression of derived traits most commonly found in species of the genusHomo most recent, such as crown symmetry, lingual reduction and simplified dentin surface of the third premolar.
“More fossil and genetic findings will be necessary to evaluate the taxonomy of the“ non-erectus ”populations of the Middle Asian Pleistocene, such as the Tongzi hominids, who could be good candidates for the Denisovan lineage,” says María Martinón-Torres .
Possible Candidates: Denisovans
They're a Neanderthal-related population which inhabited Asia during the late Middle Pleistocene and Upper Pleistocene, and which was discovered in 2010 from the genetic analysis of a phalanx and a tooth found in the Denisova cave, in the Altai massif (Russia).
Abundant genetic information has been obtained from Denisovans, but there are hardly any fossil remains, so their physical appearance and their identification in the fossil record remains a mystery.
SongXing et al. "Late Middle Pleistocene hominin teeth from Tongzi, southern China"Journal of Human Evolution130: 96-108 May 2019.