[dinosaur] Opisuchus, new metriorhynchoid from Jurassic of Germany + Astorgosuchus from Oligocene of Pakistan

Ben Creisler
[email protected]

New papers:

Opisuchus meieri gen. et sp. nov.


Manuela Aiglstorfer, Philipe Havlik & Yanina Herrera (2019)
The first metriorhynchoid crocodyliform from the Aalenian (Middle Jurassic)
of Germany, with implications for the evolution of Metriorhynchoidea.
Zoological Journal of the Linnean Society, zlz072, (advance online
publication)
doi:  https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1093_zoolinnean_zlz072&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=lv0wlOFHdqxn1xmhDPLqfYfWJA7AAfmC_VASee8dOQ4&s=QDjuoPyqXKhfs2ip0SD1pIEhobfaSRy8WHhmJcWriWY&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__academic.oup.com_zoolinnean_advance-2Darticle-2Dabstract_doi_10.1093_zoolinnean_zlz072_5611050&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=lv0wlOFHdqxn1xmhDPLqfYfWJA7AAfmC_VASee8dOQ4&s=goLo2pdRPSOHyHR2BLtvPCX3QS504xAkNczhthNYvIc&e= 



Thalattosuchia, a clade of Mesozoic aquatic crocodyliforms, were the only
archosaurs that ever became fully adapted to marine ecosystems. They are
represented by two clades, the semiaquatic teleosauroids and the
metriorhynchoids, which include fully pelagic forms. So far, little is
known on the early evolutionary history of Metriorhynchoidea and data are
sparse, especially from the early Middle Jurassic. Opisuchus meieri gen. et
sp. nov. a metriorhynchoid crocodyliform from the early Aalenian (early
Middle Jurassic) of southern Germany, is described here. It is one of the
most complete specimens of a non-metriorhynchid metriorhynchoid, and the
best-preserved thalattosuchian described from the Aalenian. The new taxon
is represented by a nearly complete skull, which has a unique combination
of characters distinguishing it from other species of Metriorhynchoidea. It
displays a mosaic of plesiomorphic and apomorphic morphological features
that sheds new light on early metriorhynchoid evolution. This taxon is an
important puzzle piece, which will help to better track the mosaic
character distribution in Thalattosuchia.

====


Astorgosuchus gen. nov.
Astorgosuchus bugtiensis comb. nov.

Jeremy E. Martin, Pierre-Olivier Antoine, Vincent Perrier, Jean-
Loup Welcomme, Gregoire Metais & Laurent Marivaux (2019)
A large crocodyloid from the Oligocene of the Bugti Hills, Pakistan.
Journal of Vertebrate Paleontology e1671427 (advance online publication)
https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1080_02724634.2019.1671427&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=lv0wlOFHdqxn1xmhDPLqfYfWJA7AAfmC_VASee8dOQ4&s=zEoTpEuTU7SbfeqIe-M-XchJaAda-GcUc2GbWxnHNoQ&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.tandfonline.com_doi_full_10.1080_02724634.2019.1671427&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=lv0wlOFHdqxn1xmhDPLqfYfWJA7AAfmC_VASee8dOQ4&s=9KdWwUqDU1Gf8pWe75B3QuA5t1KEImssbBo0Q_b4K8I&e= 

(no abstract, from the text...)

Pilgrim (1908, 1912) was the first to describe and name several crocodylian
species from the Bugti Hills, including a number of longirostrine forms
(Martin, 2018). With these remains, Pilgrim (1908) erected Crocodilus
bugtiensis, which was later described (Pilgrim, 1912) and represented by a
portion of the rostrum (IM E221) from Pishi Nala near Dera Bugti. Although
no overlapping material exists to relate the skull material described by
Pilgrim (1912) with the mandibular material described above, we consider
all these specimens to represent a single species...

The estimated size of adult A. bugtiensis falls in the range of other large
fossil Crocodylus (Brochu and Storrs, 2012; Delfino and De Vos, 2014). The
fossil record offers repeated instances of gigantism among semiaquatic
crocodylomorphs (Table 2), and based on cranial material, the largest
exemplars could be estimated to surpass a TBL of 10 m (Head, 2001; Sereno
et al., 2001; Aguilera et al., 2006; Riff and Aguilera, 2008).
Astorgosuchus bugtiensis was retrieved in the same fluviolacustrine
deposits as the large tomistomines 'Gavialis' curvirostris and 'Gavialis'
breviceps (Pilgrim, 1908, 1912; Martin, 2018). Both ‘Gavialis’ taxa cooccur
with several megaherbivores, such as rhinocerotoids and chalicotheriids
among perissodactyls, anthracotheriid artiodactyls, and proboscideans
(Antoine et al., 2003, 2004, 2013; Métais et al., 2009a; Lihoreau et al.,
2017).


<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.avg.com_email-2Dsignature-3Futm-5Fmedium-3Demail-26utm-5Fsource-3Dlink-26utm-5Fcampaign-3Dsig-2Demail-26utm-5Fcontent-3Dwebmail&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=lv0wlOFHdqxn1xmhDPLqfYfWJA7AAfmC_VASee8dOQ4&s=BSCxGtMbUUkyy74hAj8da49TrTfZECXBbfmArO-5tvY&e= >
Virus-free.
www.avg.com
<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.avg.com_email-2Dsignature-3Futm-5Fmedium-3Demail-26utm-5Fsource-3Dlink-26utm-5Fcampaign-3Dsig-2Demail-26utm-5Fcontent-3Dwebmail&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=lv0wlOFHdqxn1xmhDPLqfYfWJA7AAfmC_VASee8dOQ4&s=BSCxGtMbUUkyy74hAj8da49TrTfZECXBbfmArO-5tvY&e= >
<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>