[dinosaur] Polar dinosaur feather assemblage from Australia

Ben Creisler
[email protected]

A new paper:

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Martin Kundrát, Thomas H. Rich, Johan Lindgren, Peter Sjövall, Patricia
Vickers-Rich, Luis M.Chiappe & Benjamin P.Kear (2019)
A polar dinosaur feather assemblage from Australia.
Gondwana Research (advance online publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1016_j.gr.2019.10.004&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=TOzJRJgyyJ0ZnMb_LjfmBVgi0S7WGPYNrSxrIXlkqhA&s=8ilChHlp9ZnUVtRK6rBQRXEohGlf3H6LVeJTyVeLTZo&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.sciencedirect.com_science_article_abs_pii_S1342937X19302850&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=TOzJRJgyyJ0ZnMb_LjfmBVgi0S7WGPYNrSxrIXlkqhA&s=gxLCkqWndu_tJ2_5e21Uif0F0VbjN3pvEJEkIh_4viE&e= 

Highlights

Fossil feathers from the Koonwarra Fossil Bed in southeastern Australia
record the first demonstrable dinosaur (including birds) integumentary
structures described from the Mesozoic polar regions.
This diverse range of non-avian theropod (paravian) and bird feathers more
than doubles the number of Mesozoic fossil feather specimens and
morphologies recovered from the Gondwanan landmasses to date.
Possible traces of eumelanosomes imply original dark colouration and
patterning. Some of the geologically oldest barbicel-like structures also
evince advanced avian-grade flight feather morphologies in the Early
Cretaceous.

ABSTRACT

Exceptionally preserved Mesozoic feathered dinosaur fossils (including
birds) are famous, but recognized from only very few localities worldwide,
and are especially rare in the Southern Hemisphere. Here we report an
assemblage of non-avian and avian dinosaur feathers from an Early
Cretaceous polar (around 70°S) environment in what is now southeastern
Australia. The recovered remains incorporate small (10–30 mm long) basal
paravian-like tufted body feathers, open-vaned contour feathers, and
asymmetrical bird-like wing feathers that possess high-angled barbs with
possible remnants of barbicels — amongst the geologically oldest observed
to date. Such morphological diversity augments scant skeletal evidence for
a range of insulated non-avian theropods and birds inhabiting extreme
southern high-latitude settings during the Mesozoic. Although some of these
fossil feathers exhibit what may be residual patterning, most are uniformly
toned and preserve rod-shaped microbodies, as well as densely-packed
microbody imprints on the barbules that are structurally consistent with
eumelanosomes. Geochemical analysis detected no identifiable residual
biomolecules, which we suspect were lost via hydrolysis and oxidization
during diagenesis and weathering. Nevertheless, an originally dark
pigmentation can be reasonably inferred from these melanic traces, which
like the coloured feathers of modern birds, might have facilitated crypsis,
visual communication and/or thermoregulation in a cold polar habitat.