[dinosaur] Maniraptoran affinities for Cretaceous European 'geckoid' eggshells
Ben Creisler <[email protected]> Sat, 11 Jan 2020 11:02:18 -0800
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--00000000000080410b059be1e225 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: Quoted-printable Ben Creisler [email protected] A new paper: Seung Choi, Miguel Moreno=E2=80=90Azanza, Zolt=C3=A1n Csiki=E2=80=90Sava,= Edina Prondvai & Yuong=E2=80=90Nam Lee (2020) Comparative crystallography suggests maniraptoran theropod affinities for latest Cretaceous European 'geckoid' eggshell. Papers in Palaeontology (advance online publication) doi: https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.org_10.1002= _spp2.1294&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DR= y_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DBcfavg1yHQXJfyzLgwcrOaguKjaX= h4s_a9iquxJgdqw&s=3DiM6VZG15Y9FX4uQyPaMaX5vxojEWd2mhaieczKSotbw&e=3D=20 https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__onlinelibrary.wiley.= com_doi_10.1002_spp2.1294&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p= 7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DBcfavg1yHQXJf= yzLgwcrOaguKjaXh4s_a9iquxJgdqw&s=3Dqmkb0cw3RR0vWJpikNzRNTSQ3os3j5IWsrEbbfls= KMk&e=3D=20 Data for this study are available in the Dryad Digital Repository: https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.org_10.5061_drya= d.v75qf08&d=3DDwIFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy= _mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DBcfavg1yHQXJfyzLgwcrOaguKjaXh= 4s_a9iquxJgdqw&s=3Dg7re_ro1Jh6bvnc-rTp6FoHx40ft1OyenUosFPL6goI&e=3D=20 Thin fossil eggshell from Upper Cretaceous deposits of Europe, characterized by nodular ornamentation similar to modern gekkotan eggshell, has mostly been interpreted as gekkotan (=3D'geckoid') in origin. However, = in some cases, as for the oogenus Pseudogeckoolithus, a theropod affinity has also been suggested. The true affinity of these fossil 'geckoid' eggshells has remained controversial due to the absence of analytical methods for identifying genuine gecko eggshell in the fossil record. In this study, we apply electron backscatter diffraction (EBSD) analysis to latest Cretaceous European 'geckoid' (including Pseudogeckoolithus) eggshell, in comparison with modern gekkotan and theropod (avian) eggshell. We found that Pseudogeckoolithus has a definite theropod eggshell=E2=80=90like crystallog= raphic configuration, in clear contrast to that seen in modern 'gecko eggshells'. Furthermore, the crystallography of the nodular ornamentation in Pseudogeckoolithus is similar to that seen in megapode eggshell, but different from that of gecko eggshell, despite superficial morphological similarity. The remarkable morphological similarities between Pseudogeckoolithus and modern gecko eggshells are thus convergent, and the 'gekkotan affinity' hypothesis can be dismissed for Pseudogeckoolithus. This study provides a template for differentiating true gekkotan from dinosaurian eggshells in the fossil record. The potential functional significance of eggshell ornamentation, lost in most modern birds, requires further study, and experimental zoological approach may shed light on this issue. Finally, the present results suggest caution about the dangers of using potentially homoplastic eggshell characters in eggshell parataxonomy. =3D=3D=3D=3D=3D=3D=3D=3D --00000000000080410b059be1e225 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: Quoted-printable <div dir=3D"ltr">Ben Creisler<div><a href=3D"mailto:[email protected]">bc= [email protected]</a></div><div><br></div><div>A new paper:<br><div><br></d= iv><div>Seung Choi, =C2=A0Miguel Moreno=E2=80=90Azanza, =C2=A0Zolt=C3=A1n C= siki=E2=80=90Sava, =C2=A0Edina Prondvai =C2=A0& Yuong=E2=80=90Nam Lee (= 2020)<br>Comparative crystallography suggests maniraptoran theropod affinit= ies for latest Cretaceous European 'geckoid' eggshell.<br>Papers in= Palaeontology (advance online publication)<br>doi: <a href=3D"https://urld= efense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.org_10.1002_spp2.1294&d= =3DDwMFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=3DRy_mO= 4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DBcfavg1yHQXJfyzLgwcrOaguKjaX= h4s_a9iquxJgdqw&s=3DiM6VZG15Y9FX4uQyPaMaX5vxojEWd2mhaieczKSotbw&e= =3D">https://doi.org/10.1002/spp2.1294</a><br><a href=3D"https://urldefense= .proofpoint.com/v2/url?u=3Dhttps-3A__onlinelibrary.wiley.com_doi_10.1002_sp= p2.1294&d=3DDwMFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&= amp;r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DBcfavg1yHQXJfyz= LgwcrOaguKjaXh4s_a9iquxJgdqw&s=3Dqmkb0cw3RR0vWJpikNzRNTSQ3os3j5IWsrEbbf= lsKMk&e=3D">https://onlinelibrary.wiley.com/doi/10.1002/spp2.1294</a><b= r><br>Data for this study are available in the Dryad Digital Repository: <a= href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__doi.org_10.= 5061_dryad.v75qf08&d=3DDwMFaQ&c=3DclK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8= p7CSfnc_gI&r=3DRy_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3DBcfa= vg1yHQXJfyzLgwcrOaguKjaXh4s_a9iquxJgdqw&s=3Dg7re_ro1Jh6bvnc-rTp6FoHx40f= t1OyenUosFPL6goI&e=3D">https://doi.org/10.5061/dryad.v75qf08</a></div><= div><br><br>Thin fossil eggshell from Upper Cretaceous deposits of Europe, = characterized by nodular ornamentation similar to modern gekkotan eggshell,= has mostly been interpreted as gekkotan (=3D'geckoid') in origin. = However, in some cases, as for the oogenus Pseudogeckoolithus, a theropod a= ffinity has also been suggested. The true affinity of these fossil 'gec= koid' eggshells has remained controversial due to the absence of analyt= ical methods for identifying genuine gecko eggshell in the fossil record. I= n this study, we apply electron backscatter diffraction (EBSD) analysis to = latest Cretaceous European 'geckoid' (including Pseudogeckoolithus)= eggshell, in comparison with modern gekkotan and theropod (avian) eggshell= . We found that Pseudogeckoolithus has a definite theropod eggshell=E2=80= =90like crystallographic configuration, in clear contrast to that seen in m= odern 'gecko eggshells'. Furthermore, the crystallography of the no= dular ornamentation in Pseudogeckoolithus is similar to that seen in megapo= de eggshell, but different from that of gecko eggshell, despite superficial= morphological similarity. The remarkable morphological similarities betwee= n Pseudogeckoolithus and modern gecko eggshells are thus convergent, and th= e 'gekkotan affinity' hypothesis can be dismissed for Pseudogeckool= ithus. This study provides a template for differentiating true gekkotan fro= m dinosaurian eggshells in the fossil record. The potential functional sign= ificance of eggshell ornamentation, lost in most modern birds, requires fur= ther study, and experimental zoological approach may shed light on this iss= ue. Finally, the present results suggest caution about the dangers of using= potentially homoplastic eggshell characters in eggshell parataxonomy.<br><= br>=3D=3D=3D=3D=3D=3D=3D=3D<br></div></div></div> --00000000000080410b059be1e225--