[dinosaur] Fossil turtles from Upper Cretaceous Arlington Archosaur Site + subadult Psephochelys (placodont)
Ben Creisler <[email protected]> Tue, 24 Dec 2019 12:15:39 -0800
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--000000000000797223059a78cf81 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: Quoted-printable Ben [email protected]=0A=0ANew non-dino papers:=0A=0A=0A=3D=3D= =3D=0A=0AFree pdf:=0A=0A "Trinitichelys" maini sp. nov.=0A=0ABrent Adrian, = Heather F. Smith, Christopher R. Noto, and Aryeh Grossman=0A(2019)=0AA new = baenid, "Trinitichelys" maini sp. nov., and other fossil turtles from=0Athe= Upper Cretaceous Arlington Archosaur Site (Woodbine Formation,=0ACenomania= n), Texas, USA.=0APalaeontologia Electronica 22.3.81 1=E2=80=9329.=0Adoi: h= ttps://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.org_10.26879_1001= &d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUm= Gof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DHiqbOzT470D-Nd9FsBFZaul3YmtoKa9Smz8lPK= yj6ew&s=3Dv9ypbAWckfcNQS7ugcCEuLIkNqiPjAYiFYNLsWH10HQ&e=3D=20=0Ahttps://url= defense.proofpoint.com/v2/url?u=3Dhttps-3A__palaeo-2Delectronica.org_conten= t_2019_2876-2Darlington-2Darchosaur-2Dturtles&d=3DDwIFaQ&c=3DclK7kQUTWtAVEO= VIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9= SI&m=3DHiqbOzT470D-Nd9FsBFZaul3YmtoKa9Smz8lPKyj6ew&s=3DPADOlElhV6RE8bVsFv8d= 9aR5Po-rEOoEF35XlaSnjc8&e=3D=20=0AFree pdf:=0Ahttps://urldefense.proofpoint= .com/v2/url?u=3Dhttps-3A__palaeo-2Delectronica.org_content_pdfs_1001.pdf&d= =3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGo= f_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DHiqbOzT470D-Nd9FsBFZaul3YmtoKa9Smz8lPKyj= 6ew&s=3D5wxv-7lE9CJiouU98R5IJO4bD5V2PplDx_vqihy3lis&e=3D=20=0A=0A=0AThe Arl= ington Archosaur Site (AAS) is a Cenomanian (93-99 Mya) fossil=0Alocality i= n the Woodbine Formation of Texas. Woodbine deposits form=0Aprimarily terri= genous near shore and shallow marine depositional systems,=0Aincluding shel= f, deltaic, and fluvial environments. The AAS is the oldest=0AUpper Cretace= ous unit in the Gulf Coastal Plain, and the most complete=0Afossil ecosyste= m discovered in southwestern Appalachia. It preserves a=0Afreshwater/bracki= sh wetland situated in a low-lying coastal plain. The site=0Acontains diver= se fossil vertebrate and invertebrate faunas and abundant=0Acarbonized plan= t material. The taphonomy of the site is complex, frequently=0Aresulting in= fragmentary specimens due to a mixture of environmental=0Atransport, biolo= gical accumulation, pervasive crocodyliform predation,=0Amassive storms, wi= ldfires, and widespread flooding events. Numerous new=0Areptilian taxa (par= ticularly crocodyliform) have been recently described,=0Abut turtles from t= he site have not been taxonomically identified. This=0Astudy documents foss= il shell material of AAS turtles, most of which were=0Apreviously unknown f= rom the site. Results include a new baenid species,=0A"Trinitichelys" maini= sp. nov., numerous elements of the helochelydrid=0ANaomichelys, a small tr= ionychid, and a bothremydid. Insights from the=0Aturtle faunas at the AAS c= ontribute to our growing understanding of the=0Acoastal ecosystems of south= western Appalachia at the beginning of the Upper=0ACretaceous.=0A=0A=3D=3D= =3D=3D=3D=3D=3D=3D=0A=0AWei Wang, Feimin Ma & Chun Li (2019)=0AFirst suba= dult specimen of Psephochelys polyosteoderma (Sauropterygia,=0APlacodontia)= implies turtle=E2=80=90like fusion pattern of the carapace=0ALetters in Pa= laeontology (advance online publication)=0Adoi: https://urldefense.proofpoi= nt.com/v2/url?u=3Dhttps-3A__doi.org_10.1002_spp2.1293&d=3DDwIFaQ&c=3DclK7kQ= UTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z= 1CYJgFW9SI&m=3DHiqbOzT470D-Nd9FsBFZaul3YmtoKa9Smz8lPKyj6ew&s=3D8nsuIyiG-IZq= XqyzyjxZNDCHUd4z0WrJTT4F2YVqxmE&e=3D=20=0Ahttps://urldefense.proofpoint.com= /v2/url?u=3Dhttps-3A__onlinelibrary.wiley.com_doi_10.1002_spp2.1293&d=3DDwI= FaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9M= yZgecRCKHn5g4z1CYJgFW9SI&m=3DHiqbOzT470D-Nd9FsBFZaul3YmtoKa9Smz8lPKyj6ew&s= =3Dxwhk6yzSvQzrAaay6mkY9I76AHrXMhi3Pzl9WoFZbpU&e=3D=20=0A=0A=0A=0APlacodont= s are a group of turtle=E2=80=90like animals, including placochelyids that= =0Aare restricted entirely to the Triassic Tethyan realm. Their fossil rema= ins=0Aare rare compared with other contemporaneous marine reptiles. Here, w= e=0Areport the first subadult specimen of the placochelyid Psephochelys=0Ap= olyosteoderma from south=E2=80=90western China. It is the most complete spe= cimen=0Aof this taxon known. The new fossil is referred confidently to Psep= hochelys=0Apolyosteoderma on the basis of the narrow and spatulate rostrum,= toothless=0Apremaxillae, and carapace composed of small and numerous armou= r plates with=0Arelatively smooth surfaces. The new specimen provides addit= ional anatomical=0Ainformation for Psephochelys polyosteoderma including th= e presence of=0Atransverse processes on the dorsal vertebrae lacking antero= posterior=0Aexpansion, and a phalangeal formula in the pes of 1=E2=80=902= =E2=80=903=E2=80=904=E2=80=902. The phylogeny=0Aof placodonts, especially t= he family Placochelyidae, is revised based on a=0Acharacter matrix incorpor= ating additional postcranial characters. This=0Aresulted in a better=E2=80= =90resolved tree when compared with previous studies,=0Awith Psephochelys a= s a derived genus within Placochelyidae. On comparison=0Awith the adult hol= otype specimen, the incompletely developed armour in the=0Anew specimen rev= eals a fusion pattern of the carapace beginning with the=0Aaxial and margin= al regions. This surface fusion pattern resembles the=0Aontogenetic process= in the embryonic turtle shell, hinting at a possible=0Adeep homology with = their common diapsid ancestor.=0A= --000000000000797223059a78cf81 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: Quoted-printable <div dir=3D"ltr"><div><br></div><div>Ben Creisler</div><div><a href=3D"mail= to:[email protected]">[email protected]</a></div><div><br></div><div>Ne= w non-dino papers:</div><div><br></div><div><br></div><div>=3D=3D=3D</div><= div><br></div><div>Free pdf:</div><div><br>=C2=A0"Trinitichelys" = maini sp. nov.=C2=A0</div><div><br>Brent Adrian, Heather F. Smith, Christop= her R. Noto, and Aryeh Grossman (2019)<br>A new baenid, "Trinitichelys= " maini sp. nov., and other fossil turtles from the Upper Cretaceous A= rlington Archosaur Site (Woodbine Formation, Cenomanian), Texas, USA. <br>P= alaeontologia Electronica 22.3.81 1=E2=80=9329. <br>doi: <a href=3D"https:/= /urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.org_10.26879_1001&d= =3DDwMFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO= 4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DHiqbOzT470D-Nd9FsBFZaul3Ymto= Ka9Smz8lPKyj6ew&s=3Dv9ypbAWckfcNQS7ugcCEuLIkNqiPjAYiFYNLsWH10HQ&e= =3D">https://doi.org/10.26879/1001</a><br><a href=3D"https://urldefense.pro= ofpoint.com/v2/url?u=3Dhttps-3A__palaeo-2Delectronica.org_content_2019_2876= -2Darlington-2Darchosaur-2Dturtles&d=3DDwMFaQ&c=3DclK7kQUTWtAVEOVIg= vi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW= 9SI&m=3DHiqbOzT470D-Nd9FsBFZaul3YmtoKa9Smz8lPKyj6ew&s=3DPADOlElhV6R= E8bVsFv8d9aR5Po-rEOoEF35XlaSnjc8&e=3D">https://palaeo-electronica.org/c= ontent/2019/2876-arlington-archosaur-turtles</a><br>Free pdf:<br><a href=3D= "https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__palaeo-2Delectronic= a.org_content_pdfs_1001.pdf&d=3DDwMFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5B= OUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&= ;m=3DHiqbOzT470D-Nd9FsBFZaul3YmtoKa9Smz8lPKyj6ew&s=3D5wxv-7lE9CJiouU98R= 5IJO4bD5V2PplDx_vqihy3lis&e=3D">https://palaeo-electronica.org/content/= pdfs/1001.pdf</a><br><br><br>The Arlington Archosaur Site (AAS) is a Cenoma= nian (93-99 Mya) fossil locality in the Woodbine Formation of Texas. Woodbi= ne deposits form primarily terrigenous near shore and shallow marine deposi= tional systems, including shelf, deltaic, and fluvial environments. The AAS= is the oldest Upper Cretaceous unit in the Gulf Coastal Plain, and the mos= t complete fossil ecosystem discovered in southwestern Appalachia. It prese= rves a freshwater/brackish wetland situated in a low-lying coastal plain. T= he site contains diverse fossil vertebrate and invertebrate faunas and abun= dant carbonized plant material. The taphonomy of the site is complex, frequ= ently resulting in fragmentary specimens due to a mixture of environmental = transport, biological accumulation, pervasive crocodyliform predation, mass= ive storms, wildfires, and widespread flooding events. Numerous new reptili= an taxa (particularly crocodyliform) have been recently described, but turt= les from the site have not been taxonomically identified. This study docume= nts fossil shell material of AAS turtles, most of which were previously unk= nown from the site. Results include a new baenid species, "Trinitichel= ys" maini sp. nov., numerous elements of the helochelydrid Naomichelys= , a small trionychid, and a bothremydid. Insights from the turtle faunas at= the AAS contribute to our growing understanding of the coastal ecosystems = of southwestern Appalachia at the beginning of the Upper Cretaceous.<br><br= >=3D=3D=3D=3D=3D=3D=3D=3D</div><div><br>Wei Wang, =C2=A0Feimin Ma & =C2= =A0Chun Li (2019)<br>First subadult specimen of Psephochelys polyosteoderma= (Sauropterygia, Placodontia) implies turtle=E2=80=90like fusion pattern of= the carapace<br>Letters in Palaeontology (advance online publication)<br>d= oi: <a href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.o= rg_10.1002_spp2.1293&d=3DDwMFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0= H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DHi= qbOzT470D-Nd9FsBFZaul3YmtoKa9Smz8lPKyj6ew&s=3D8nsuIyiG-IZqXqyzyjxZNDCHU= d4z0WrJTT4F2YVqxmE&e=3D">https://doi.org/10.1002/spp2.1293</a><br><a hr= ef=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__onlinelibrary.= wiley.com_doi_10.1002_spp2.1293&d=3DDwMFaQ&c=3DclK7kQUTWtAVEOVIgvi0= NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI= &m=3DHiqbOzT470D-Nd9FsBFZaul3YmtoKa9Smz8lPKyj6ew&s=3Dxwhk6yzSvQzrAa= ay6mkY9I76AHrXMhi3Pzl9WoFZbpU&e=3D">https://onlinelibrary.wiley.com/doi= /10.1002/spp2.1293</a><br><br><br><br>Placodonts are a group of turtle=E2= =80=90like animals, including placochelyids that are restricted entirely to= the Triassic Tethyan realm. Their fossil remains are rare compared with ot= her contemporaneous marine reptiles. Here, we report the first subadult spe= cimen of the placochelyid Psephochelys polyosteoderma from south=E2=80=90we= stern China. It is the most complete specimen of this taxon known. The new = fossil is referred confidently to Psephochelys polyosteoderma on the basis = of the narrow and spatulate rostrum, toothless premaxillae, and carapace co= mposed of small and numerous armour plates with relatively smooth surfaces.= The new specimen provides additional anatomical information for Psephochel= ys polyosteoderma including the presence of transverse processes on the dor= sal vertebrae lacking anteroposterior expansion, and a phalangeal formula i= n the pes of 1=E2=80=902=E2=80=903=E2=80=904=E2=80=902. The phylogeny of pl= acodonts, especially the family Placochelyidae, is revised based on a chara= cter matrix incorporating additional postcranial characters. This resulted = in a better=E2=80=90resolved tree when compared with previous studies, with= Psephochelys as a derived genus within Placochelyidae. On comparison with = the adult holotype specimen, the incompletely developed armour in the new s= pecimen reveals a fusion pattern of the carapace beginning with the axial a= nd marginal regions. This surface fusion pattern resembles the ontogenetic = process in the embryonic turtle shell, hinting at a possible deep homology = with their common diapsid ancestor.<br><br><br></div><div><br></div><br><di= v><br></div></div>=0A= --000000000000797223059a78cf81--