[dinosaur] Cassowary syrinx, hyoid and larynx + jawed vertebrate timetree + Late Triassic Bristol fissure + dino crabs

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Ben [email protected]=0A=0ASome recent non-dino papers that ma=
y be of interest:=0A=0AFree pdf:=0A=0APhoebe L. McInerney, Michael S. Y. Le=
e, Alice M. Clement & Trevor H. Worthy=0A(2019)=0AThe phylogenetic signific=
ance of the morphology of the syrinx, hyoid and=0Alarynx, of the southern c=
assowary, Casuarius casuarius (Aves,=0APalaeognathae).=0ABMC Evolutionary B=
iology 19, Article number: 233=0Adoi:  https://urldefense.proofpoint.com/v2=
/url?u=3Dhttps-3A__doi.org_10.1186_s12862-2D019-2D1544-2D7&d=3DDwIFaQ&c=3Dc=
lK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKH=
n5g4z1CYJgFW9SI&m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs&s=3DjJSiZOi=
t2yHpfsrgunw68mM24LV0taecI2N9PgSOMyw&e=3D=20=0Ahttps://urldefense.proofpoin=
t.com/v2/url?u=3Dhttps-3A__bmcevolbiol.biomedcentral.com_articles_10.1186_s=
12862-2D019-2D1544-2D7&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CS=
fnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DnqWyZuGTuGybTb7l=
uXRVQinr2ZxWPoat1tOL0BjErSs&s=3DvPf0Sox29L2KD4kIFPJ93K7WTBVif__i0Z5CojyRUzg=
&e=3D=20=0A=0AFree pdf:=0Ahttps://urldefense.proofpoint.com/v2/url?u=3Dhttp=
s-3A__bmcevolbiol.biomedcentral.com_track_pdf_10.1186_s12862-2D019-2D1544-2=
D7&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFa=
UmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL=
0BjErSs&s=3DvpYgFoJBVbCGaUlb0TOJJNl6FUyfFunzzwg-6O4JRPM&e=3D=20=0A=0A=0ABac=
kground=0A=0APalaeognathae is a basal clade within Aves and include the lar=
ge and=0Aflightless ratites and the smaller, volant tinamous. Although much=
 research=0Ahas been conducted on various aspects of palaeognath morphology=
, ecology,=0Aand evolutionary history, there are still areas which require=
=0Ainvestigation. This study aimed to fill gaps in our knowledge of the=0AS=
outhern Cassowary, Casuarius casuarius, for which information on the=0Askel=
etal systems of the syrinx, hyoid and larynx is lacking - despite these=0As=
tructures having been recognised as performing key functional roles=0Aassoc=
iated with vocalisation, respiration and feeding. Previous research=0Ainto =
the syrinx and hyoid have also indicated these structures to be=0Avaluable =
for determining evolutionary relationships among neognath taxa,=0Aand thus =
suggest they would also be informative for palaeognath=0Aphylogenetic analy=
ses, which still exhibits strong conflict between=0Amorphological and molec=
ular trees.=0A=0AResults=0A=0AThe morphology of the syrinx, hyoid and laryn=
x of C. casuarius is described=0Afrom CT scans. The syrinx is of the simple=
 tracheo-bronchial syrinx type,=0Alacking specialised elements such as the =
pessulus; the hyoid is relatively=0Ashort with longer ceratobranchials comp=
ared to epibranchials; and the=0Alarynx is comprised of entirely cartilagin=
ous, standard avian anatomical=0Aelements including a concave, basin-like c=
ricoid and fused cricoid wings.=0AAs in the larynx, both the syrinx and hyo=
id lack ossification and all three=0Astructures were most similar to Dromai=
us. We documented substantial=0Avariation across palaeognaths in the skelet=
al character states of the=0Asyrinx, hyoid, and larynx, using both the lite=
rature and novel observations=0A(e.g. of C. casuarius). Notably, new synapo=
morphies linking=0ADinornithiformes and Tinamidae are identified, consisten=
t with the=0Amolecular evidence for this clade. These shared morphological =
character=0Atraits include the ossification of the cricoid and arytenoid ca=
rtilages,=0Aand an additional cranial character, the articulation between t=
he maxillary=0Aprocess of the nasal and the maxilla.=0A=0AConclusion=0A=0AS=
yrinx, hyoid and larynx characters of palaeognaths display greater=0Aconcor=
dance with molecular trees than do other morphological traits. These=0Astru=
ctures might therefore be less prone to homoplasy related to=0Aflightlessne=
ss and gigantism, compared to typical morphological traits=0Aemphasised in =
previous phylogenetic studies.=0A=0A=3D=3D=3D=3D=0A=0AFree pdf:=0A=0AGiovan=
ni Mussini, David I. Whiteside, Claudia Hildebrandt & Michael J.=0ABenton (=
2019)=0AAnatomy of a Late Triassic Bristol fissure: Tytherington fissure 2.=
=0AProceedings of the Geologists' Association (advance online publication)=
=0Adoi: https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.org_10.1=
016_j.pgeola.2019.12.001&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7=
CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DnqWyZuGTuGybTb=
7luXRVQinr2ZxWPoat1tOL0BjErSs&s=3DbXo_n_d_vDqdJBXEN1diV2TSbzqKLF5ancOzvNnqN=
3s&e=3D=20=0Ahttps://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__www.sci=
encedirect.com_science_article_abs_pii_S0016787819301415&d=3DDwIFaQ&c=3DclK=
7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5=
g4z1CYJgFW9SI&m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs&s=3DZxryTO024=
JuXMSKcONs_EaP1obe7_aSTbr6P-q_9ARQ&e=3D=20=0A=0A=0AFree pdf:=0Ahttps://urld=
efense.proofpoint.com/v2/url?u=3Dhttps-3A__cpb-2Deu-2Dw2.wpmucdn.com_blogs.=
bristol.ac.uk_dist_6_525_files_2019_12_2020Mussini.pdf&d=3DDwIFaQ&c=3DclK7k=
QUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4=
z1CYJgFW9SI&m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs&s=3DptBhhJiQTY6=
UErksCdn-hW-xpLlOGWDzogHv0ToZTlo&e=3D=20=0A=0A=0A=0A=0AThe Late Triassic an=
d Early Jurassic fissures around Bristol and South=0AWales are famous as so=
urces of excellent fossils of early mammals,=0Adinosaurs, sphenodontians, a=
nd other tetrapods. However, the ways in which=0Athese fissures filled with=
 sediment have not often been documented.=0AMoreover, systematic faunal sam=
pling up a working face exposure has rarely=0Abeen attempted for the UK Tri=
assic fissures. Here we show in detail how a=0Acomplex fissure in Tythering=
ton Quarry, north-east of Bristol, filled in=0Amultiple steps, and document=
 both sedimentary facies and faunas.=0ATytherington Quarry is a key Late Tr=
iassic Bristol sauropsid fissure site,=0Ahaving previously yielded abundant=
 Thecodontosaurus remains and a new genus=0Aof sphenodontian, Diphydontosau=
rus. Our findings comprise specimens of=0Aterrestrial reptiles, including s=
phenodontians and archosaurs. However,=0Aabundant remains of fishes and mar=
ine invertebrates were also recovered,=0Aindicating a significant marine in=
fluence during parts of the=0Afissure-filling process. Comparisons of our r=
esults with those of previous=0Astudies on Tytherington and other Late Tria=
ssic SW UK fissure sites=0Aindicate some consistent patterns of faunal asso=
ciation and provide further=0Aevidence of a Rhaetian age for the Late Trias=
sic palaeo-island fissures=0Anorth of Bristol. Our analysis supports a mode=
l of fissure formation and=0Afilling entailing punctuated episodes of sedim=
entation through a relatively=0Ashort time.=0A=0A=3D=3D=3D=0A=0AFree pdf:=
=0A=0ADavid Marjanovic (2019)=0ARecalibrating the transcriptomic timetree o=
f jawed vertebrates.=0AbioRxiv 2019.12.19.882829 (preprint)=0Adoi: https://=
urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.org_10.1101_2019.12.19.8=
82829&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4=
IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1=
tOL0BjErSs&s=3DDpnnioae3ACVDdKHQykBvv5bRA6ZSYzq1ZhiAtSVFKw&e=3D=20=0Ahttps:=
//urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__www.biorxiv.org_content_10=
.1101_2019.12.19.882829v1&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p=
7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DnqWyZuGTuGybT=
b7luXRVQinr2ZxWPoat1tOL0BjErSs&s=3D-8ZmXOo2_qJNX6vUTi0zjUDVVhsO13oK_avYRJh0=
FaA&e=3D=20=0A=0AFree pdf:=0Ahttps://urldefense.proofpoint.com/v2/url?u=3Dh=
ttps-3A__www.biorxiv.org_content_10.1101_2019.12.19.882829v1.full.pdf&d=3DD=
wIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl=
9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs&=
s=3DYzCGrOXVlmuUgAE9zldMgPr25sP-0uYR06U9RGDXDWo&e=3D=20=0A=0A=0AMolecular d=
ivergence dating has the potential to overcome the=0Aincompleteness of the =
fossil record in inferring when cladogenetic events=0A(splits, divergences)=
 happened, but needs to be calibrated by the fossil=0Arecord. Ideally but u=
nrealistically, this would require practitioners to be=0Aspecialists in mol=
ecular evolution, in the phylogeny and the fossil record=0Aof all sampled t=
axa, and in the chronostratigraphy of the sites the fossils=0Awere found in=
. Paleontologists have therefore tried to help by publishing=0Acompendia of=
 recommended calibrations, and molecular biologists unfamiliar=0Awith the f=
ossil record have made heavy use of such works. Using a recent=0Aexample of=
 a large timetree inferred from molecular data, I demonstrate=0Athat calibr=
ation dates cannot be taken from published compendia without=0Arisking stro=
ng distortions to the results, because compendia become=0Aoutdated faster t=
han they are published. The present work cannot serve as=0Asuch a compendiu=
m either; in the slightly longer term, it can only=0Ahighlight known and ov=
erlooked problems. Future authors will need to solve=0Aeach of these proble=
ms anew through a thorough search of the primary=0Apaleobiological and chro=
nostratigraphic literature on each calibration date=0Aevery time they infer=
 a new timetree; over 40% of the sources I cite were=0Apublished after mid-=
2016. Treating all calibrations as soft bounds results=0Ain younger nodes t=
han treating all calibrations as hard bounds. The=0Aunexpected exception ar=
e nodes calibrated with both minimum and maximum=0Aages, further demonstrat=
ing the widely underestimated importance of maximum=0Aages in divergence da=
ting.=0A=0A=0A=0A=3D=3D=3D=3D=3D=0A=3D=3D=3D=3D=3D=0A=0AAlso:=0A=0ANinon Ro=
bin, Barry W. M. van Bakel, Mat=C3=BA=C5=A1 Hy=C5=BEn=C3=BD, Aude Cincotta,=
 G=C3=A9raldine=0AGarcia, Sylvain Charbonnier, Pascal Godefroit & Xavier Va=
lentin  (2019)=0AThe oldest freshwater crabs: claws on dinosaur bones.=0ASc=
ientific Reports  9, Article number: 20220=0Adoi: https://urldefense.proofp=
oint.com/v2/url?u=3Dhttps-3A__doi.org_10.1038_s41598-2D019-2D56180-2Dw&d=3D=
DwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Y=
l9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs=
&s=3D-E2zjAlqr50gKvK3OI0wKmx3NH8NzuZUF3K1ej6mQYk&e=3D=20=0Ahttps://urldefen=
se.proofpoint.com/v2/url?u=3Dhttps-3A__www.nature.com_articles_s41598-2D019=
-2D56180-2Dw&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=
=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DnqWyZuGTuGybTb7luXRVQinr=
2ZxWPoat1tOL0BjErSs&s=3DYOrF4ATi0eD0_M0n42dCZK-3CacLbI64DMcBBSyjJls&e=3D=20=
=0A=0AFree pdf:=0Ahttps://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__ww=
w.nature.com_articles_s41598-2D019-2D56180-2Dw.pdf&d=3DDwIFaQ&c=3DclK7kQUTW=
tAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CY=
JgFW9SI&m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs&s=3DLSMvLu2zAKfNEbW=
txlzTh8jYooJm8ng7OJL7NmV86ec&e=3D=20=0A=0AWith approximately 1,500 extant s=
pecies, freshwater crabs (Decapoda:=0ABrachyura) are among the most diverse=
 decapod crustaceans. Nevertheless,=0Atheir fossil record is extremely limi=
ted: only Potamidae, Potamonautidae=0Aand Trichodactylidae are reported up =
to the Eocene of the Neotropics so=0Afar. This work documents unusually lar=
ge decapod claws from the Upper=0ACretaceous (Campanian) continental deposi=
ts of Velaux and vicinity=0A(southern France), in close association with la=
rge vertebrate remains. In=0Aaddition to (1) the systematic assignment of t=
hese claws, the study=0Aaddresses (2) the salinity trends in the deposit en=
vironment from its=0Afaunal assemblage and the elementary chemical patterns=
 of fossils, and (3)=0Athe likely scenario for their auto/allochthony in th=
e Velaux fluvial=0Asystem. These claws belong to a new taxon, Dinocarcinus =
velauciensis n.=0Agen. n. sp., referred to as Portunoidea sensu lato, a gro=
up of "true" crabs=0Anowadays linked to marine systems. However, the faunal=
 assemblage, the claw=0Ataphonomy and the carbonates Y/Ho signatures suppor=
t their ancient=0Afreshwater/terrestrial ecology, making them the oldest re=
ported continental=0Abrachyurans and extending the presence of crabs in fre=
shwater environments=0Aby 40 Ma. Either as primary or as secondary freshwat=
er crabs, the=0Aoccurrence of these portunoids in Velaux is an evidence for=
 the independent=0Acolonizations of continental environments by multiple br=
achyuran clades=0Aover time, as early as the Campanian.=0A=

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<div dir=3D"ltr"><br><div>Ben Creisler</div><div><a href=3D"mailto:bcreisle=
[email protected]">[email protected]</a></div><div><br></div><div>Some recent n=
on-dino papers that may be of interest:</div><div><br></div><div>Free pdf:<=
/div><div><br>Phoebe L. McInerney, Michael S. Y. Lee, Alice M. Clement &amp=
; Trevor H. Worthy (2019)<br>The phylogenetic significance of the morpholog=
y of the syrinx, hyoid and larynx, of the southern cassowary, Casuarius cas=
uarius (Aves, Palaeognathae).<br>BMC Evolutionary Biology 19, Article numbe=
r: 233 <br>doi: =C2=A0<a href=3D"https://urldefense.proofpoint.com/v2/url?u=
=3Dhttps-3A__doi.org_10.1186_s12862-2D019-2D1544-2D7&amp;d=3DDwMFaQ&amp;c=
=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9My=
ZgecRCKHn5g4z1CYJgFW9SI&amp;m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs=
&amp;s=3DjJSiZOit2yHpfsrgunw68mM24LV0taecI2N9PgSOMyw&amp;e=3D">https://doi.=
org/10.1186/s12862-019-1544-7</a><br><a href=3D"https://urldefense.proofpoi=
nt.com/v2/url?u=3Dhttps-3A__bmcevolbiol.biomedcentral.com_articles_10.1186_=
s12862-2D019-2D1544-2D7&amp;d=3DDwMFaQ&amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHh=
pN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=
=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs&amp;s=3DvPf0Sox29L2KD4kIFPJ9=
3K7WTBVif__i0Z5CojyRUzg&amp;e=3D">https://bmcevolbiol.biomedcentral.com/art=
icles/10.1186/s12862-019-1544-7</a><br><br>Free pdf:<br><a href=3D"https://=
urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__bmcevolbiol.biomedcentral.co=
m_track_pdf_10.1186_s12862-2D019-2D1544-2D7&amp;d=3DDwMFaQ&amp;c=3DclK7kQUT=
WtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g=
4z1CYJgFW9SI&amp;m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs&amp;s=3Dvp=
YgFoJBVbCGaUlb0TOJJNl6FUyfFunzzwg-6O4JRPM&amp;e=3D">https://bmcevolbiol.bio=
medcentral.com/track/pdf/10.1186/s12862-019-1544-7</a></div><div><br></div>=
<div><br>Background</div><div><br>Palaeognathae is a basal clade within Ave=
s and include the large and flightless ratites and the smaller, volant tina=
mous. Although much research has been conducted on various aspects of palae=
ognath morphology, ecology, and evolutionary history, there are still areas=
 which require investigation. This study aimed to fill gaps in our knowledg=
e of the Southern Cassowary, Casuarius casuarius, for which information on =
the skeletal systems of the syrinx, hyoid and larynx is lacking - despite t=
hese structures having been recognised as performing key functional roles a=
ssociated with vocalisation, respiration and feeding. Previous research int=
o the syrinx and hyoid have also indicated these structures to be valuable =
for determining evolutionary relationships among neognath taxa, and thus su=
ggest they would also be informative for palaeognath phylogenetic analyses,=
 which still exhibits strong conflict between morphological and molecular t=
rees.<br><br>Results</div><div><br>The morphology of the syrinx, hyoid and =
larynx of C. casuarius is described from CT scans. The syrinx is of the sim=
ple tracheo-bronchial syrinx type, lacking specialised elements such as the=
 pessulus; the hyoid is relatively short with longer ceratobranchials compa=
red to epibranchials; and the larynx is comprised of entirely cartilaginous=
, standard avian anatomical elements including a concave, basin-like cricoi=
d and fused cricoid wings. As in the larynx, both the syrinx and hyoid lack=
 ossification and all three structures were most similar to Dromaius. We do=
cumented substantial variation across palaeognaths in the skeletal characte=
r states of the syrinx, hyoid, and larynx, using both the literature and no=
vel observations (e.g. of C. casuarius). Notably, new synapomorphies linkin=
g Dinornithiformes and Tinamidae are identified, consistent with the molecu=
lar evidence for this clade. These shared morphological character traits in=
clude the ossification of the cricoid and arytenoid cartilages, and an addi=
tional cranial character, the articulation between the maxillary process of=
 the nasal and the maxilla.<br><br>Conclusion</div><div><br>Syrinx, hyoid a=
nd larynx characters of palaeognaths display greater concordance with molec=
ular trees than do other morphological traits. These structures might there=
fore be less prone to homoplasy related to flightlessness and gigantism, co=
mpared to typical morphological traits emphasised in previous phylogenetic =
studies.<br></div><div><br></div><div>=3D=3D=3D=3D</div><div><br></div><div=
>Free pdf:</div><div><br></div><div>Giovanni Mussini, David I. Whiteside, C=
laudia Hildebrandt &amp; Michael J. Benton (2019)<br>Anatomy of a Late Tria=
ssic Bristol fissure: Tytherington fissure 2.<br>Proceedings of the Geologi=
sts&#39; Association (advance online publication)<br>doi: <a href=3D"https:=
//urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.org_10.1016_j.pgeola.2=
019.12.001&amp;d=3DDwMFaQ&amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_=
gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=3DnqWyZuGTuGyb=
Tb7luXRVQinr2ZxWPoat1tOL0BjErSs&amp;s=3DbXo_n_d_vDqdJBXEN1diV2TSbzqKLF5ancO=
zvNnqN3s&amp;e=3D" target=3D"_blank">https://doi.org/10.1016/j.pgeola.2019.=
12.001</a> <br><a href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttp=
s-3A__www.sciencedirect.com_science_article_abs_pii_S0016787819301415&amp;d=
=3DDwMFaQ&amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO=
4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=3DnqWyZuGTuGybTb7luXRVQinr2ZxW=
Poat1tOL0BjErSs&amp;s=3DZxryTO024JuXMSKcONs_EaP1obe7_aSTbr6P-q_9ARQ&amp;e=
=3D" target=3D"_blank">https://www.sciencedirect.com/science/article/abs/pi=
i/S0016787819301415</a><br><br><br>Free pdf:<br><a href=3D"https://urldefen=
se.proofpoint.com/v2/url?u=3Dhttps-3A__cpb-2Deu-2Dw2.wpmucdn.com_blogs.bris=
tol.ac.uk_dist_6_525_files_2019_12_2020Mussini.pdf&amp;d=3DDwMFaQ&amp;c=3Dc=
lK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgec=
RCKHn5g4z1CYJgFW9SI&amp;m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs&amp=
;s=3DptBhhJiQTY6UErksCdn-hW-xpLlOGWDzogHv0ToZTlo&amp;e=3D">https://cpb-eu-w=
2.wpmucdn.com/blogs.bristol.ac.uk/dist/6/525/files/2019/12/2020Mussini.pdf<=
/a>=C2=A0=C2=A0</div><div><br></div><div><br></div><div><br>The Late Triass=
ic and Early Jurassic fissures around Bristol and South Wales are famous as=
 sources of excellent fossils of early mammals, dinosaurs, sphenodontians, =
and other tetrapods. However, the ways in which these fissures filled with =
sediment have not often been documented. Moreover, systematic faunal sampli=
ng up a working face exposure has rarely been attempted for the UK Triassic=
 fissures. Here we show in detail how a complex fissure in Tytherington Qua=
rry, north-east of Bristol, filled in multiple steps, and document both sed=
imentary facies and faunas. Tytherington Quarry is a key Late Triassic Bris=
tol sauropsid fissure site, having previously yielded abundant Thecodontosa=
urus remains and a new genus of sphenodontian, Diphydontosaurus. Our findin=
gs comprise specimens of terrestrial reptiles, including sphenodontians and=
 archosaurs. However, abundant remains of fishes and marine invertebrates w=
ere also recovered, indicating a significant marine influence during parts =
of the fissure-filling process. Comparisons of our results with those of pr=
evious studies on Tytherington and other Late Triassic SW UK fissure sites =
indicate some consistent patterns of faunal association and provide further=
 evidence of a Rhaetian age for the Late Triassic palaeo-island fissures no=
rth of Bristol. Our analysis supports a model of fissure formation and fill=
ing entailing punctuated episodes of sedimentation through a relatively sho=
rt time.</div><div><br></div><div>=3D=3D=3D</div><div><br></div><div>Free p=
df:</div><div><br>David Marjanovic (2019)<br>Recalibrating the transcriptom=
ic timetree of jawed vertebrates.<br>bioRxiv 2019.12.19.882829 (preprint) <=
br>doi: <a href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__d=
oi.org_10.1101_2019.12.19.882829&amp;d=3DDwMFaQ&amp;c=3DclK7kQUTWtAVEOVIgvi=
0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9S=
I&amp;m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs&amp;s=3DDpnnioae3ACVD=
dKHQykBvv5bRA6ZSYzq1ZhiAtSVFKw&amp;e=3D">https://doi.org/10.1101/2019.12.19=
.882829</a><br><a href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttp=
s-3A__www.biorxiv.org_content_10.1101_2019.12.19.882829v1&amp;d=3DDwMFaQ&am=
p;c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl=
9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjE=
rSs&amp;s=3D-8ZmXOo2_qJNX6vUTi0zjUDVVhsO13oK_avYRJh0FaA&amp;e=3D">https://w=
ww.biorxiv.org/content/10.1101/2019.12.19.882829v1</a></div><div><br></div>=
<div>Free pdf:</div><div><a href=3D"https://urldefense.proofpoint.com/v2/ur=
l?u=3Dhttps-3A__www.biorxiv.org_content_10.1101_2019.12.19.882829v1.full.pd=
f&amp;d=3DDwMFaQ&amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=
=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=3DnqWyZuGTuGybTb7luXRV=
Qinr2ZxWPoat1tOL0BjErSs&amp;s=3DYzCGrOXVlmuUgAE9zldMgPr25sP-0uYR06U9RGDXDWo=
&amp;e=3D">https://www.biorxiv.org/content/10.1101/2019.12.19.882829v1.full=
.pdf</a><br></div><div><br></div><div>=C2=A0<br></div><div>Molecular diverg=
ence dating has the potential to overcome the incompleteness of the fossil =
record in inferring when cladogenetic events (splits, divergences) happened=
, but needs to be calibrated by the fossil record. Ideally but unrealistica=
lly, this would require practitioners to be specialists in molecular evolut=
ion, in the phylogeny and the fossil record of all sampled taxa, and in the=
 chronostratigraphy of the sites the fossils were found in. Paleontologists=
 have therefore tried to help by publishing compendia of recommended calibr=
ations, and molecular biologists unfamiliar with the fossil record have mad=
e heavy use of such works. Using a recent example of a large timetree infer=
red from molecular data, I demonstrate that calibration dates cannot be tak=
en from published compendia without risking strong distortions to the resul=
ts, because compendia become outdated faster than they are published. The p=
resent work cannot serve as such a compendium either; in the slightly longe=
r term, it can only highlight known and overlooked problems. Future authors=
 will need to solve each of these problems anew through a thorough search o=
f the primary paleobiological and chronostratigraphic literature on each ca=
libration date every time they infer a new timetree; over 40% of the source=
s I cite were published after mid-2016. Treating all calibrations as soft b=
ounds results in younger nodes than treating all calibrations as hard bound=
s. The unexpected exception are nodes calibrated with both minimum and maxi=
mum ages, further demonstrating the widely underestimated importance of max=
imum ages in divergence dating.<br><br><br></div><div><br>=3D=3D=3D=3D=3D<b=
r></div><div>=3D=3D=3D=3D=3D</div><div><br></div><div>Also:</div><div><br><=
/div><div>Ninon Robin, Barry W. M. van Bakel, Mat=C3=BA=C5=A1 Hy=C5=BEn=C3=
=BD, Aude Cincotta, G=C3=A9raldine Garcia, Sylvain Charbonnier, Pascal Gode=
froit &amp; Xavier Valentin =C2=A0(2019)<br>The oldest freshwater crabs: cl=
aws on dinosaur bones.<br>Scientific Reports =C2=A09, Article number: 20220=
<br>doi: <a href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__=
doi.org_10.1038_s41598-2D019-2D56180-2Dw&amp;d=3DDwMFaQ&amp;c=3DclK7kQUTWtA=
VEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1=
CYJgFW9SI&amp;m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs&amp;s=3D-E2zj=
Alqr50gKvK3OI0wKmx3NH8NzuZUF3K1ej6mQYk&amp;e=3D">https://doi.org/10.1038/s4=
1598-019-56180-w</a><br><a href=3D"https://urldefense.proofpoint.com/v2/url=
?u=3Dhttps-3A__www.nature.com_articles_s41598-2D019-2D56180-2Dw&amp;d=3DDwM=
FaQ&amp;c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUm=
Gof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&amp;m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1t=
OL0BjErSs&amp;s=3DYOrF4ATi0eD0_M0n42dCZK-3CacLbI64DMcBBSyjJls&amp;e=3D">htt=
ps://www.nature.com/articles/s41598-019-56180-w</a></div><div><br>Free pdf:=
<br><a href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__www.n=
ature.com_articles_s41598-2D019-2D56180-2Dw.pdf&amp;d=3DDwMFaQ&amp;c=3DclK7=
kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCK=
Hn5g4z1CYJgFW9SI&amp;m=3DnqWyZuGTuGybTb7luXRVQinr2ZxWPoat1tOL0BjErSs&amp;s=
=3DLSMvLu2zAKfNEbWtxlzTh8jYooJm8ng7OJL7NmV86ec&amp;e=3D">https://www.nature=
.com/articles/s41598-019-56180-w.pdf</a><br><br>With approximately 1,500 ex=
tant species, freshwater crabs (Decapoda: Brachyura) are among the most div=
erse decapod crustaceans. Nevertheless, their fossil record is extremely li=
mited: 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 o=
f Velaux and vicinity (southern France), in close association with large ve=
rtebrate remains. In addition to (1) the systematic assignment of these cla=
ws, 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/allochthony in the Velaux fluvi=
al system. These claws belong to a new taxon, Dinocarcinus velauciensis n. =
gen. n. sp., referred to as Portunoidea sensu lato, a group of &quot;true&q=
uot; crabs nowadays linked to marine systems. However, the faunal assemblag=
e, the claw taphonomy and the carbonates Y/Ho signatures support their anci=
ent freshwater/terrestrial ecology, making them the oldest reported contine=
ntal brachyurans and extending the presence of crabs in freshwater environm=
ents by 40=E2=80=89Ma. Either as primary or as secondary freshwater crabs, =
the occurrence of these portunoids in Velaux is an evidence for the indepen=
dent colonizations of continental environments by multiple brachyuran clade=
s over time, as early as the Campanian.<br></div></div>=0A=

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