Puschel, T. A. | bioRxiv Science

bioRxiv2026

Infant corpse carrying in Pan reflects maternal attachment and death context

Infant corpse carrying is widely observed in chimpanzees and bonobos, yet its underlying mechanisms remain debated. Analysing 83 published cases using Bayesian mixed-effects models, we show that ICC duration varies with infant age at death, cause of death, and site-level interbirth intervals, with longer carrying following disease-related deaths, older infant age, and slower life histories. These results suggest that variation in infant corpse carrying duration is parsimoniously accounted for by the persistence of maternal behavioural systems being modulated by carrying risk, dyadic bond strength, and life-history context rather than by mothers recognising death as an irreversible biological state. Given the close evolutionary relationship of Pan and Homo, this implies that the complex cognitive frameworks required to recognise deaths finality likely emerged in the hominin lineage after divergence from the Pan-Homo last common ancestor.

animal behavior and cognition↗

bioRxiv2024

Hominin brain size increase has emerged from within-species encephalization

The fact that rapid brain size increase was clearly a key aspect of human evolution has prompted many studies focussing on this phenomenon1-4, and many suggestions as to the underlying evolutionary patterns and processes5-10. No study to date has however separated out the contributions of change through time within-vs. between-hominin species whilst simultaneously incorporating effects of body size. Using a phylogenetic approach never applied before to palaeoanthropological data, we show that brain size increase across ~ 7 million years of hominin evolution arose from increases within individual species which account for an observed overall increase in relative brain size. Variation among species in brain size after accounting for this effect is associated with body mass differences but not time. In addition, our analysis also reveals that the within-species trend escalated in more recent lineages, implying an overall pattern of accelerating brain size increase through time.

paleontology↗

bioRxiv2021

The first Miocene fossils from coastal woodlands in the southern East African Rift

The Miocene is a key time in the evolution of African mammals and their ecosystems witnessing the origin of the African apes and the isolation of eastern coastal forests through an expanding biogeographic arid corridor. Until recently, however, Miocene sites from the southeastern regions of the continent were unknown. Here we report discovery of the first Miocene fossil teeth from the shoulders of the Urema Rift in Gorongosa National Park, Mozambique, at the southern East African Rift System. We provide the first 1) radiometric age determinations of the fossiliferous Mazamba Formation, 2) reconstructions of past vegetation in the region based on pedogenic carbonates and fossil wood, and 3) description of fossil teeth from the southern rift. Gorongosa is unique in the East African Rift System in combining marine invertebrates, marine vertebrates, terrestrial mammals, and fossil woods in coastal paleoenvironments. The Gorongosa fossil sites offer the first evidence of persistent woodlands and forests on the coastal margins of southeastern Africa during the Miocene, and an exceptional assemblage of fossil vertebrates including new species. Further work will allow the testing of hypotheses positing the formation of a northeast-southwest arid corridor isolating species on the eastern coastal forests from those elsewhere in Africa. BriefThe Miocene is a key time in the evolution of African mammals and their ecosystems encompassing hominine origins and the establishment of an arid corridor that isolated eastern Africas coastal forests. Until now, however, Miocene sites from southeastern Africa have been unknown. We report the discovery of the first Miocene fossil sites from Gorongosa National Park, Mozambique, and show that these sites formed in coastal settings. We provide radiometric ages for the fossiliferous sediments, reconstructions of past vegetation based on stable isotopes and fossil wood, and a description of the first fossil teeth from the region. Gorongosa is the only paleontological site in the East African Rift that combines fossil woods, marine invertebrates, marine vertebrates, and terrestrial mammals. Gorongosa offers the first evidence of persistent woodlands and forests on the coastal margins of southeastern Africa during the Miocene.

paleontology↗