Paul C. H. Albers

"Frans de Waal (1948–2024): Editor-in-Chief of Behaviour" published on 19 Aug 2024 by Brill.

The scientific utility of Eugène Dubois' Pithecanthropus erectus (P.e.) Skullcap (Trinil 1), Femur I (Trinil 3) and associated paleontological specimens has been impaired for over a century by questions about their provenience. Firsthand accounts and contemporaneous field photographs, presented here, extensively document the site geology and discovery history. The P.e. specimens and numerous-other fossils were unearthed in 1891- 1893 from small excavations dug into a flat-lying bonebed exposed near the seasonal low water level of the Solo River along its incised left embankment. Dubois' on-site supervisors specified that the two P.e. fossils came from a ~0.2-m-thick bonebed subunit traced at a single elevation for ~12m from the 1891 Skullcap pit (~30m 2 ) to the 1892 Femur-discovery excavation and across an enlarged 1892-1893 trench (~170m 2 ). The depositional co-occurrence of the finds is supported by key documentation: the supervisors' letters to Dubois about Femur I; his initial reporting to the Indies government; 1892-1893 accounts about expanding excavation of the Femur I stratum; Dubois' 1891 1893 government submissions and 1894-1896 publications; confirmation by the Selenka Expedition in 1907-1908; Dubois' annotations on unpublished site photographs; and a letter he wrote the year he died. Field studies in the 1930s to 1970s confirmed the essential aspects of the site geology. The bonebed of 1891-1893 contained fossils referable to the extinct Trinil fauna species Axis lydekkeri , Duboisia santeng and Stegodon trigonocephalus . The Selenka Expedition excavations had a similar assemblage in the same stratigraphic position which they named the Hauptknochenschicht. The bonebed was thin bioclast-rich gravelly volcaniclastic sandstone with taphonomic and sedimentary features indicating an unusual origin. Bioclasts range from proboscidean craniums and logs to rat teeth, freshwater mollusc shells and leaves. The terrestrial-vertebrate skeletal elements are overwhelmingly disarticulated and frequently broken. Their surfaces are little-abraded by fluvial transport. The bone fossilization is quite uniform. More than one-hundred ungulate individuals perished. No evidence has been found of hominin- or terrestrial-carnivore involvement. The bioclasts varied in density from place-to-place and vertically, and were matrix supported in the bonebed. No substantial internal depositional hiatus was reported. In combination with Trinil's paleogeographic context, these features implicate a catastrophic mortality of ungulates in a population aggregation along the floodplain of a perennial paleo-river, followed by lahar-flood transport and deposition of gravel-size lithic- and biotic-materials. Trinil provides evidence favoring a broad archaic-hominin presence in southern Sundaland. The Trinil fauna is a lynch-pin in a long-lasting paleobiogeographic association between H. erectus and certain lineages of large bovids, cervids, proboscideans, rhinoceros, suids and tiger. The bonebed's paleogeographic setting exemplifies the stratovolcanic drainages that H. erectus occupied for >0.8 million years in Java, including the watershed of a marine delta ~150km east of Trinil, a volcanic island ~100km north of Trinil, and areas to its west for 500km (where species associated with Trinil H. erectus occur). In the Java Sea (Sunda Shelf), seismic data image immense Pleistocene river- and coastal-terranes which archaic hominins and other large-mammals, like those at Trinil, might have inhabited.

Some of the earliest evidence for the presence of modern humans in rainforests has come from the fossil deposits of Lida Ajer in Sumatra. Two human teeth from this cave were estimated to be 73–63 thousand years old, which is significantly older than some estimates of modern human migration out of Africa based on genetic data. The deposits were interpreted as being associated with a rainforest environment based largely on the presence of abundant orangutan fossils. As well as the main fossil-bearing chamber, fossil-bearing passages are present below a sinkhole, although the relationship between the different fossil deposits has only been tenuously established. Here, we provide significant new sedimentological, geochronological and palaeoecological data aimed at reconstructing the speleological and environmental history of the cave and the clastic and fossil deposits therein. Our data suggest that the Lida Ajer fossils were deposited during Marine Isotope Stage 4, with fossils from the lower passages older than the main fossil chamber. Our use of stable carbon and oxygen isotope analyses of mammalian tooth enamel demonstrates that early humans probably occupied a closed-canopy forest very similar to those present in the region today, although the fossil orangutans may have occupied a slightly different niche. This article is part of the theme issue ‘Tropical forests in the deep human past’.

Over 60 years ago, stone tools and remains of megafauna were discovered on the Southeast Asian islands of Flores, Sulawesi and Luzon, and a Middle Pleistocene colonization by Homo erectus was initially proposed to have occurred on these islands^1,2,3,4. However, until the discovery of Homo floresiensis in 2003, claims of the presence of archaic hominins on Wallacean islands were hypothetical owing to the absence of in situ fossils and/or stone artefacts that were excavated from well-documented stratigraphic contexts, or because secure numerical dating methods of these sites were lacking. As a consequence, these claims were generally treated with scepticism⁵. Here we describe the results of recent excavations at Kalinga in the Cagayan Valley of northern Luzon in the Philippines that have yielded 57 stone tools associated with an almost-complete disarticulated skeleton of Rhinoceros philippinensis, which shows clear signs of butchery, together with other fossil fauna remains attributed to stegodon, Philippine brown deer, freshwater turtle and monitor lizard. All finds originate from a clay-rich bone bed that was dated to between 777 and 631 thousand years ago using electron-spin resonance methods that were applied to tooth enamel and fluvial quartz. This evidence pushes back the proven period of colonization⁶ of the Philippines by hundreds of thousands of years, and furthermore suggests that early overseas dispersal in Island South East Asia by premodern hominins took place several times during the Early and Middle Pleistocene stages^1,2,3,4. The Philippines therefore may have had a central role in southward movements into Wallacea, not only of Pleistocene megafauna⁷, but also of archaic hominins.

Three nothosaur skulls from the Lower Muschelkalk (Lower Anisian) locality of Winterswijk, the Netherlands, were recently acquired by museum Twentse Welle (Enschede) and have thereby become available for scientific description. Thus, these skulls had been identified asNothosaurus winterswijkensis, but upon examination these skulls challenge the status of thisNothosaurus species. All diagnostic characters are somehow discredited, but the material can also not be unequivocably be considered asNothosaurus marchicus, which is the only other obvious candidate. As these fossils originate from the same strata as the type ofNothosaurus winterswijkensisand there is no reason to assume that the animals occupied different ecological niches they are more plausibly considered one species, andNothosaurus winterswijkensistherefore becomes a junior synonym ofNothosaurus marchicus. The diagnosis ofNothosaurus marchicusis enlarged to include all finds.

A new species of the genus Nothosaurus from the Lower Muschelkalk of Winterswijk, The Netherlands, shows relatively plesiomorphic features such as a relatively forward position of the pineal foramen. The jugal enters into the ventral margin of the orbit, which would also be regarded as plesiomorphic, were it not that this feature optimizes unequivocally as a reversal and, hence, as a diagnostic (derived) character of the new taxon. The new taxon does not, however, increase the fit of the cladogram for the phylogenetic relationships within Nothosaurus to the stratigraphic record of the genus. The basal position of Nothosaurus juvenilis remains problematic.

A new species of the genusNothosaurusfrom the Lower Muschelkalk of Winterswijk, The Netherlands, shows relatively plesiomorphic features such as a relatively forward position of the pineal foramen. The jugal enters into the ventral margin of the orbit, which would also be regarded as plesiomorphic, were it not that this feature optimizes unequivocally as a reversal and, hence, as a diagnostic (derived) character of the new taxon. The new taxon does not, however, increase the fit of the cladogram for the phylogenetic relationships withinNothosaurusto the stratigraphic record of the genus. The basal position ofNothosaurus juvenilisremains problematic.