Archaeology of JSARN-124 site 3, central-western Arnhem Land: Determining the age of the so-called ‘Genyornis’ painting

In 2011, Gunn et al. published the discovery in a remote part of the western Arnhem Land plateau of a rock painting that closely resembles the most recent reconstructions of an extinct megafaunal bird, the dromornithid Genyornis newtoni. Characteristics of the painting distinguish it from depictions of other bird species and support its identification as G. newtoni: a deep convex bill, unlike the shallow bill of an emu or cassowary; a globular cranium and relatively thick neck; indication of a crop (emus and cassowaries lack crops); non-pendulous posture of the wing (unlike the pendulous posture of emus); the proportions of the pelvic limb showing long tibiotarsi and stout tarsometatarsi; the short, broad toes that appear to terminate in blunt claws; and a dorsal profile paralleling that of reconstructed dromornithids and unlike an emu or any species of cassowary, in which the vertex of the back is more anterior. The several points of special resemblance between the painting and reconstructions of the extinct bird based on paleontological evidence led Gunn et al. (2011:10) to conclude, ‘on the basis of probability the painting is indeed a representation of Genyornis newtoni’. This finding brings a conundrum. If the painting is indeed a contemporaneous depiction of G. newtoni, it becomes the oldest painting known in the world, for the bird is thought to have become extinct around 50,000 +/- 5000 years ago (Miller et al. 1999; Roberts and Brook 2010; Roberts et al. 2001) or even earlier (see Grellet-Tinner et al. 2016). Or that timing for the extinction of Genyornis is wrong; or a relic population survived longer on the Arnhem Land plateau (e.g. Murray and Vickers-Rich 2004), perhaps until the Last Glacial Maximum (LGM), which commenced around 25,000 years ago. And, as Gunn et al. (2011) acknowledged, there are still other alternatives. The painting might be of a ‘mythological’ animal: either one rooted in ancient memory of G. newtoni, as has been suggested for the ‘mihirung’ of southern Australian Aboriginal peoples (Vickers-Rich 1987) – although in societies without writing, social memory has not been found anywhere in the world to reliably extend in recognisable form over very long periods of time (cf. Bradley 2002) – or of a creature without a material counterpart that fortuitously resembled the fossil bird. The painting occurs on a vertical rock wall under a shallow overhang. Could the motif really have survived there since Pleistocene times, whether 25,000 or 50,000 years ago? And the painting shows a speared bird, so it could be the first evidence for the hunting of extinct megafauna in Australia. With these enigmas in mind, the Jawoyn Association asked us in 2010 to study the ‘Genyornis’ site, to investigate the age of the art and its archaeological and geomorphological context. Our major aims were to ask whether the painting dates, or theoretically could date, to the time of G. newtoni, or whether it must be more recent, and to uncover contextual ancient cultural information relating to the artworks and to occupation activities at the site in the past. Here, we present the results of these archaeological and geomorphological investigations along with a summary of the chemistry of the rock surface that houses the painting of the large bird thought by Gunn et al. (2011) to be of a Genyornis.

Fossil birds from the Roof of the World: The first avian fauna from High Asia and its implications for late Quaternary environments in Eastern Pamir

The Eastern Pamir (eastern Tajikistan) is a high-mountain plateau with elevations up to 7000 m, currently characterized by extremely severe environmental conditions and harboring a specialized montane fauna, which in part is shared with that of the Tibetan Plateau. The modern bird fauna of High Asia comprises a diversity of both ancient and recently diverged endemics, and thus is of general importance for historical biogeography and understanding the origin of modern high mountain ecosystems. However, the past history of the Central Asian highland avian communities remains practically unknown, as no fossil bird assemblages from high elevation areas were previously reported. In particular, it remains completely unexplored how birds responded to late Quaternary climatic fluctuations. Here we report the first fossil bird fauna from the High Asia and the first fossil birds from Tajikistan. An assemblage from the late Pleistocene through middle Holocene of Istykskaya cave (4060 m) in Eastern Pamir surprisingly comprises a remarkable diversity of waterbirds, including a few species that are completely absent from High Asia today and that were not reported globally from such high altitudes. The diversity of waterbirds incudes taxa of various ecological preferences (shorebirds, underwater and surface feeders, both zoophagous and phytophagous), strongly indicating the presence of a productive waterbody at the vicinity of the site in the past. These observations correspond to recent palaeoclimatic data, implying increased water availability in this region, currently occupied by high mountain semi-deserts. Our findings for the first time show that milder environmental conditions of late Quaternary attracted lowland species to the Central Asian highland wetlands. The reported assemblage yet contains several characteristic highland taxa, indicating a long-time persistence of some Central Asian montane faunistic elements. In particular, it includes the Tibetan Sandgrouse (Syrrhaptes tibetanus), a highly-specialized montane dweller, which is for the first time found in the fossil record.

A phasianid bird from the Pleistocene of Tainan: the very first avian fossil from Taiwan

Taiwan accommodates more than 600 avian species, including about 30 endemic ones. As yet, however, no fossil birds have been scientifically documented from Taiwan, so that the evolutionary origins of this diversified avifauna remain elusive. Here we report on the very first fossil bird from Taiwan. This Pleistocene specimen, a distal end of the left tarsometatarsus, shows diagnostic features of the galliform Phasianidae, including an asymmetric plantar articular facet trochlea metatarsi III. Our discovery of a Pleistocene phasianid from Taiwan opens a new perspective on studies of the evolution of the avifauna in Taiwan because the fossil shows that careful search for fossils in suitable localities has the potential of recovering avian remains. In general, East Asia has an extremely poor avian fossil record, especially if terrestrial birds are concerned, which impedes well-founded evolutionary scenarios concerning the arrival of certain groups in the area. The Phasianidae exhibit a high degree of endemism in Taiwan, and the new fossil presents the first physical evidence for the presence of phasianids on the island, some 400,000–800,000 years ago. The specimen belongs to a species the size of the three larger phasianids occurring in Taiwan today (Syrmaticus mikado, Lophura swinhoii, and Phasianus colchicus). Still, an unambiguous assignment to either of these species is not possible due to the incomplete nature of the left tarsometatarsus. Because the former two species are endemic to Taiwan, the fossil has the potential to yield the first data on their existence in the geological past of Taiwan if future finds allow identification on species-level.

Evidence for Holocene ice sheet history from geomorphology, cosmogenic isotopes, and bird vomit, East Antarctica.

<p>The post-LGM thinning history of the East Antarctic Ice Sheet is not yet well constrained. Here we report some integrated observations and analyses that constrain the ice sheet thinning history in Western Dronning Maud Land and Coats Land, adjacent to the easternmost Weddell Sea, which is a key area of uncertainty in ice sheet reconstructions. Geomorphological observations show a distinct series of weathering zones with fresh erratics only found in a relatively narrow zone above the present ice sheet margin. We report cosmogenic surface exposure dates of erratics in the different weathering zones, using <sup>10</sup>Be and in situ <sup>14</sup>C. We further report a large number of radiocarbon ages on sub-fossil bird vomit (regurgitated proventricular stomach oil, sometimes termed ‘mumiyo’) from nesting snow petrels (Pagodroma nivea) which record periods of ice sheet absence. Together these analyses allow us to determine a more tightly constrained thinning history of the ice sheet in this sector. We discuss the implications of this thinning history for geologically-based ice sheet reconstructions and for ice sheet models.</p>

Disassociated rhamphotheca of fossil bird Confuciusornis informs early beak reconstruction, stress regime, and developmental patterns

Soft tissue preservation in fossil birds provides a rare window into their anatomy, function, and development. Here, we present an exceptionally-preserved specimen of Confuciusornis which, through Laser-Stimulated Fluorescence imaging, is identified as preserving a disassociated rhamphotheca. Reconstruction of the in vivo position of the rhamphotheca validates the association of the rhamphotheca with two previous confuciusornithid specimens while calling that of a third specimen into question. The ease of dissociation is discussed and proposed with a fourth specimen alongside finite element analysis as evidence for preferential soft-food feeding. However, this proposition remains tentative until there is a better understanding of the functional role of beak attachment in living birds. Differences in post-rostral extent and possibly rhamphotheca curvature between confuciusornithids and modern birds hint at developmental differences between the two. Together, this information provides a wealth of new information regarding the nature of the beak outside crown Aves.

An early Oligocene stem Galbulae (jacamars and puffbirds) from southern France, and the position of the Paleogene family Sylphornithidae

Together, puffbirds (Bucconidae) and jacamars (Galbulidae) form the suborder Galbulae, sister group of all other Piciformes. Hitherto, the Galbulae had no ascertained pre-Pleistocene fossil record, and all previous alleged candidates have been refuted, except possibly the Sylphornithidae. Here we describe a wing of a tiny fossil bird from the early Oligocene of the Luberon region (southern France), which we assign to the Galbulae, as a new genus and species. Several characters, especially of the ulna and wing phalanx 1 of digit II, exclude the Passeriformes and Zygodactylidae, and indicate a representative of the Piciformes. Among Piciformes, absence of papillae remigales caudales and several characters of the wing phalanx 1 of digit II make it possible to assign the fossil to the Galbulae, and exclude all other clades. The fossil Sylphornithidae, with the carpometacarpus of Sylphornis being available, show some similarity with the Luberon fossil. The combination of features of the wing elements leads to the placement of the new fossil as stem Galbulae, and tentatively within the family Sylphornithidae. As such, it fills a gap and permits to better assign the whole enigmatic tiny sylphornithids, otherwise essentially known from leg bones. This yields the first firm pre-Pleistocene fossil record for the Galbulae. Today, both the Bucconidae and Galbulidae live exclusively in tropical America. The presence of stem Galbulae in the Oligocene of Europe, and probably the late Eocene, is a new example of a present-day Neotropical clade that had stem representatives in the Paleogene of Europe.

Early Paleocene landbird supports rapid phylogenetic and morphological diversification of crown birds after the K–Pg mass extinction

Evidence is accumulating for a rapid diversification of birds following the K–Pg extinction. Recent molecular divergence dating studies suggest that birds radiated explosively during the first few million years of the Paleocene; however, fossils from this interval remain poorly represented, hindering our understanding of morphological and ecological specialization in early neoavian birds. Here we report a small fossil bird from the Nacimiento Formation of New Mexico, constrained to 62.221–62.517 Ma. This partial skeleton represents the oldest arboreal crown group bird known. Phylogenetic analyses recoveredTsidiiyazhi abinigen. et sp. nov. as a member of the Sandcoleidae, an extinct basal clade of stem mousebirds (Coliiformes). The discovery ofTsidiiyazhipushes the minimum divergence ages of as many as nine additional major neoavian lineages into the earliest Paleocene, compressing the duration of the proposed explosive post–K–Pg radiation of modern birds into a very narrow temporal window parallel to that suggested for placental mammals. Simultaneously,Tsidiiyazhiprovides evidence for the rapid morphological (and likely ecological) diversification of crown birds. Features of the foot indicate semizygodactyly (the ability to facultatively reverse the fourth pedal digit), and the arcuate arrangement of the pedal trochleae bears a striking resemblance to the conformation in owls (Strigiformes). Inclusion of fossil taxa and branch length estimates impacts ancestral state reconstructions, revealing support for the independent evolution of semizygodactyly in Coliiformes, Leptosomiformes, and Strigiformes, none of which is closely related to extant clades exhibiting full zygodactyly.