[dinosaur] Reptile brain size + Wealden microvertebrate fossils + stomped turtle + more

Ben Creisler
[email protected]

Some recent mainly non-dino papers:

E. Font, R. García-Roa, D. Pincheira-Donoso & P. Carazo (2019)
Rethinking the Effects of Body Size on the Study of Brain Size Evolution.
Brain, Behavior and Evolution (advance online publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1159_000501161&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=Bb24635R0dLbegLZ6NEC78aLVCpBUd_FRkKCP6BMflU&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.karger.com_Article_Abstract_501161&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=zi8KlR6fqg7jgL2d8dReJw48utKQBy3Zo9NDtb0DG-M&e= 


Body size correlates with most structural and functional components of an
organism’s phenotype -- brain size being a prime example of allometric
scaling with animal size. Therefore, comparative studies of brain evolution
in vertebrates rely on controlling for the scaling effects of body size
variation on brain size variation by calculating brain weight/body weight
ratios. Differences in the brain size-body size relationship between taxa
are usually interpreted as differences in selection acting on the brain or
its components, while selection pressures acting on body size, which are
among the most prevalent in nature, are rarely acknowledged, leading to
conflicting and confusing conclusions. We address these problems by
comparing brain-body relationships from across >1,000 species of birds and
non-avian reptiles. Relative brain size in birds is often assumed to be 10
times larger than in reptiles of similar body size. We examine how
differences in the specific gravity of body tissues and in body design
(e.g., presence/absence of a tail or a dense shell) between these two
groups can affect estimates of relative brain size. Using phylogenetic
comparative analyses, we show that the gap in relative brain size between
birds and reptiles has been grossly exaggerated. Our results highlight the
need to take into account differences between taxa arising from selection
pressures affecting body size and design, and call into question the
widespread misconception that reptile brains are small and incapable of
supporting sophisticated behavior and cognition.

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Pernelle Turmine-Juhel, Richard Wilks, David Brockhurst, Peter A. Austen,
Christopher J. Duffin & Michael J. Benton (2019)
Microvertebrates from the Wadhurst Clay Formation (Lower Cretaceous) of
Ashdown Brickworks, East Sussex, UK.
Proceedings of the Geologists' Association (advance online publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1016_j.pgeola.2019.08.003&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=cc9jJKVUboiViDmb1zEie_1bByedSPhLTnHllTS9td8&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.sciencedirect.com_science_article_abs_pii_S0016787819300732&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=MTsrL3we_9l0veZQaeaoSfz5Ejdmx-tIEdeFCyr5u1A&e= 

Free pdf:
https://urldefense.proofpoint.com/v2/url?u=https-3A__cpb-2Deu-2Dw2.wpmucdn.com_blogs.bristol.ac.uk_dist_6_525_files_2019_08_2019Ashdown.pdf&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=awR385-DC5fLNI_dLxzwiE7mwMTNrz-m6A11XHGO-04&e= 


Ashdown Brickworks, near Bexhill, East Sussex, has produced a large number
of vertebrate fossils from the Wadhurst Clay Formation, part of the Wealden
Supergroup (Hastings Group; Valanginian; Lower Cretaceous). Here we
describe the microvertebrate fauna of the 'conglomerate bed', representing
a rich sample of taxa. While most of the recovered teeth and bones are
abraded, some heavily, most can be identified to species level. The taxa
include four species of hybodont sharks (Egertonodus basanus, Planohybodus
ensis, Polyacrodus parvidens, P. brevicostatus), three taxa of bony fishes
(an unidentified Lepidotes-like semionotiform, the pycnodontiform Ocloedus,
and an albuliform), three taxa of crocodyliforms (the goniopholid
Hulkepholis, a bernissartiid, and the atoposaurid Theriosuchus), and the
theropod dinosaurs Baryonyx and an allosauroid. Sediments of the Wadhurst
Clay Formation as a whole indicate freshwater to very slightly
brackish-water environments of deposition, and the mainly aquatic
time-averaged mixture of fishes and tetrapods recovered from the
'conglomerate bed', together with isolated terrestrial species, confirms
this interpretation.

===
Free pdf:

Christian Püntener, Jean-Paul Billon-Bruyat, Daniel Marty & Géraldine
Paratte (2019)
Under the feet of sauropods: A trampled coastal marine turtle from the Late
Jurassic of Switzerland?
Paleorxiv (preprint)
doi: 10.31233/osf.io/2atnq
https://urldefense.proofpoint.com/v2/url?u=https-3A__paleorxiv.org_2atnq&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=YnRm39jpZfd8R_hROfr8IgkDqnsa9BkaKy1ET3NMxtE&e= 


Recent excavations from the "Paléontologie A16" project brought to light
thousands of dinosaur footprints and numer-ous turtle remains from the Late
Jurassic of Porrentruy (Swiss Jura Mountains). While most fossil turtles
(Thalasso-chelydia) were found in marly layers that were deposited in a
coastal marine paleoenvironment, the dinosaur (theropods and sauropods)
tracks were found in laminites that were deposited in a tidal flat
environment. Despite extensive explo-ration, very few fossils were found in
these dinosaur track-bearing laminites. On one occasion, a sub-complete
turtle shell (Plesiochelys bigleri) was discovered within the laminites,
embedded just beneath an important sauropod track level. The state of
preservation of this specimen suggests that the turtle died on the tidal
flat and was quickly buried. This is the first evidence that these turtles
occasionally visited tidal flat paleoenvironments. Moreover, the particular
configuration of the fossil turtle suggests that the shell was possibly
trodden on by a large sauropod dinosaur.

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Jorge Avaria-Llautureo, Cristián E. Hernández, Enrique Rodríguez-Serrano &
Chris Venditti (2019)
The decoupled nature of basal metabolic rate and body temperature in
endotherm evolution
Nature 572: 651-654
DOI: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1038_s41586-2D019-2D1476-2D9&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=JtzUPm173FPArDj-wRbdVPtQ5F1M3H_cHnjTVxKXcq8&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.nature.com_articles_s41586-2D019-2D1476-2D9&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=cdXzeO5CRU4kWiBenSdSRnOy8mYMfh-6-eWd_c5GETk&e= 

The origins of endothermy in birds and mammals are important events in
vertebrate evolution. Endotherms can maintain their body temperature (Tb)
over a wide range of ambient temperatures primarily using the heat that is
generated continuously by their high basal metabolic rate (BMR)1. There is
also an important positive feedback loop as Tb influences BMR. Owing to
this interplay between BMRs and Tb, many ecologists and evolutionary
physiologists posit that the evolution of BMR and Tb must have been coupled
during the radiation of endotherms, changing with similar trends. However,
colder historical environments might have imposed strong selective
pressures on BMR to compensate for increased rates of heat loss and to keep
Tb constant. Thus, adaptation to cold ambient temperatures through
increases in BMR could have decoupled BMR from Tb and caused different
evolutionary routes to the modern diversity in these traits. Here we show
that BMR and Tb were decoupled in approximately 90% of mammalian
phylogenetic branches and 36% of avian phylogenetic branches. Mammalian
BMRs evolved with rapid bursts but without a long-term directional trend,
whereas Tb evolved mostly at a constant rate and towards colder bodies from
a warmer-bodied common ancestor. Avian BMRs evolved predominantly at a
constant rate and without a long-term directional trend, whereas Tb evolved
with much greater rate heterogeneity and with adaptive evolution towards
colder bodies. Furthermore, rapid shifts that lead to both increases and
decreases in BMRs were linked to abrupt changes towards colder ambient
temperatures—although only in mammals. Our results suggest that natural
selection effectively exploited the diversity in mammalian BMRs under
diverse, often-adverse historical thermal environments.

=======

Free pdf:

Zongji Wang, Jilin Zhang, Xiaoman Xu, Christopher C Witt, Yuan Deng,
Guangji Chen, Guanliang Meng, Shaohong Feng, Tamas Szekely, Guojie Zhang &
Qi Zhou (2019)
Phylogeny, transposable element and sex chromosome evolution of the basal
lineage of birds.
bioRxiv 750109 (online preprint publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1101_750109&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=L3ylseRFKqtAhnfnYj97F6OXXEzwpfdm8dD6FJQR4Vw&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.biorxiv.org_content_10.1101_750109v1&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=1r9CNJrQ9iKVQsAJyUrVqtGw5P3kL7feLMmue8gvQ3M&e= 

Free pdf:
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.biorxiv.org_content_biorxiv_early_2019_08_28_750109.full.pdf&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=uIYdB9MCNFvooqO_7Rjh9HfbG_JQzjnySxfczUnjQ2U&e= 


Sex chromosomes of mammals and most birds are heteromorphic, while those of
many paleognaths (ratites and tinamous) are inexplicably homomorphic. To
dissect the mechanisms underlying the different tempo of sex chromosome
evolution, we produced high-quality genomes of 12 paleognathous species,
and reconstructed their phylogeny based on alignments of the non-coding
sequences extending to nearly 40% of the genome. Our phylogenomic tree
grouped the South American rheas and tinamous together, and supported the
independent evolution of gigantism and loss of flight among ratites. The
small-bodied tinamous have much higher rates of genome-wide substitutions
and transposon turnovers. Yet majorities of both have retained
exceptionally long recombining regions occupying over half of the entire
sex chromosome, with the rest sex-linked regions diverging from each other
at a much lower rate relative to neognathous birds. Each species exhibits a
punctuated sequence divergence pattern between sex chromosomes termed
'evolutionary strata', because of stepwise suppression of recombination. We
concluded that all paleognaths share one evolutionary stratum with all
other birds, and convergently formed between one to three strata after
their rapid speciation. Contrary to the classic notion, we provided clear
evidence that the youngest stratum of some tinamous formed without
chromosomal inversion. Intriguingly, some of the encompassing W-linked
genes have upregulated their expression levels in ovary, probably due to
the female-specific selection. We proposed here that the unique male-only
parental care system of paleognaths has reduced the intensity of sexual
selection, and contributed to these species' low rates of sex chromosome
evolution. We also provided novel insights into the evolution of W-linked
genes at their early stages.


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Free pdf:

François-Nicolas Krencker, Sofie Lindström & Stéphane Bodin (2019)
A major sea-level drop briefly precedes the Toarcian oceanic anoxic event:
implication for Early Jurassic climate and carbon cycle.
Scientific Reports 9, Article number: 12518
DOI: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1038_s41598-2D019-2D48956-2Dx&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=U3b75Kx3k1ba9W8Bq2PkHCoxjugSisIAw-ZpFRxI7jk&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.nature.com_articles_s41598-2D019-2D48956-2Dx&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=noDwfqoHGSNREz1i6a3DygJoZV4TJbyxRG0IcHzOYa8&e= 
Free pdf:
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.nature.com_articles_s41598-2D019-2D48956-2Dx.pdf&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=UZ7j0XjHPHqPx5CBjNUcZ1F0dlPnJ5MUSlvuE_sAR_o&e= 


Sea-level change is an important parameter controlling the expansion of
oxygen-depleted conditions in neritic settings during oceanic anoxic events
(OAEs). Despite this fundamental role, it remains on a short timescale (<1
Myr) one of the least constrained parameters for numerous OAEs. Here we
present sedimentological and geochemical evidence from Morocco and East
Greenland showing that a forced regression shortly precedes (ca.102 kyr)
the major transgression associated with the Toarcian OAE. The forced
regression can be correlated over distances greater than 3000 km in
numerous Tethyan and Boreal basins, indicating that the relative sea-level
change was driven by eustastic fluctuations. The major amplitude (>50 m)
and short duration of the forced regression suggests that it was most
likely related to the transient waxing and waning of polar ice sheet. We
suggest that this short-lived glaciation might have a genetic link with the
inception of the Toarcian OAE. Indeed, during the deglaciation and the
accompanying sea-level rise, the thawing permafrost may have released
important quantities of methane into the atmosphere that would have
contributed to the Toarcian OAE rapid warming and its characteristic
negative carbon isotope excursion. This study offers a hypothesis on how
some hyperthermal events might be rooted in short-lived "cold-snap"
episodes.

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Free pdf:

Ninon Robin, Barry W. M. Van Bakel, Matus Hyzny, Aude Cincotta, Geraldine
Garcia, Sylvain Charbonnier, Pascal Godefroit & Xavier Valentin (2019)
The oldest freshwater crabs: claws on dinosaur bones
bioRxiv 747535
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1101_747535&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=9K5KVb_qSez3c_tS0JxBkZSkugC9riipAqGJWXwH2Z4&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.biorxiv.org_content_10.1101_747535v1&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=wsB3y4YxqIkKRdwq12cjrwKJOcXJib8FtxlaNSThBGE&s=_euBiTj3zg81iQsodXvjrQ2_f8fSab6kxbskc5ZvUwo&e= 

With approximately 1,500 extant species, freshwater crabs (Decapoda:
Brachyura) are among the most diverse decapod crustaceans. Nevertheless,
their fossil record is extremely limited: only Potamidae, Potamonautidae
and Trichodactylidae are reported up to the Eocene of the Neotropics so
far. This work documents unusually large decapod claws from the Upper
Cretaceous (Campanian) continental deposits of Velaux and vicinity
(southern France), in close association with large vertebrate remains. In
addition to (1) the systematic assignment of these claws, the study
addresses (2) the salinity trends in the deposit environment from its
faunal assemblage and the elementary chemical patterns of fossils, and (3)
the likely scenario for their auto/allochtony in the Velaux fluvial system.
These claws belong to a new taxon, Dinocarcinus velauciensis n. gen. n.
sp., referred to as Portunoidea sensu lato, a group of "true" crabs
nowadays linked to marine systems. However, the faunal assemblage, the claw
taphonomy and the carbonates Y/Ho signatures support their ancient
freshwater/terrestrial ecology, making them the oldest reported continental
brachyurans and extending the presence of crabs in freshwater environments
by 40 Ma. Either as primary or as secondary freshwater crabs, the
occurrence of these portunoids in Velaux is an evidence for the independent
colonizations of continental environments by multiple brachyuran clades
over time, as early as the Campanian.


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