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[dinosaur] Ophthalmosaurus monograph + mammal braincase sidewall origin + more





Ben Creisler
bcreisler@gmail.com


Some recent and not so recent non-dino papers:


From 2016, not yet mentioned:

B.C.  Moon & A.M. Kirton (2016) 
Ichthyosaurs of the British Middle and Upper Jurassic. Part 1 - Ophthalmosaurus Part 1. 
Monograph of the Palaeontographical Society London 170(647): 1–84
http://www.palaeosoc.org/site/shop/monographs/issue:647/


The ichthyosaur material of the British Middle and Upper Jurassic referable to Ophthalmosaurus icenicus (Ichthyosauria: Ophthalmosauridae) is revisited and re-described; this is the most completely known post-Liassic British ichthyosaur. Much of this material derives from the Callovian Oxford Clay Formation, particularly from the Peterborough Area of Cambridgeshire, UK, deposited in the Leeds Collections. Pre-Callovian ichthyosaur remains are infrequent, incomplete, and non-diagnostic. Material referred to Ophthalmosaurus icenicus shows high variability in the extent of ossification. Based on examination of the type and referred material Ophthalmosaurus monocharactus and Ophthalmosaurus pleydelli are rejected as junior subjective synonyms of Ophthalmosaurus icenicus due to a lack of diagnostic characters and pathology of specimens. Ichthyosaurus megalodeirus is rejected as a nomen nudum and the type material is referred to Ophthalmosaurus icenicus. Ophthalmosaurus icenicus is considered a separate species from Ophthalmosaurus natans based on several autapomorphies, but requires re-evaluation of the material.

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A.W. Crompton, C. Musinsky, G.W. Rougier B.-A.S. Bhullar & J. A. Miyamae (2017)
Origin of the Lateral Wall of the Mammalian Skull: Fossils, Monotremes and Therians Revisited.
Journal of Mammalian Evolution (advance online publication)
DOI: 10.1007/s10914-017-9388-7
https://link.springer.com/article/10.1007/s10914-017-9388-7


To interpret the fundamental differences in the structure and origin of the braincase sidewalls of monotremes, multituberculates, and therians, we examined MicroCT scans of a mammaliaform, Morganucodon; two non-mammalian cynodonts, Massetognathus and Probainognathus; a stem therian, Vincelestes; a juvenile and adult monotreme, Ornithorhynchus; and two marsupials, Monodelphis and Didelphis. The skull of Morganucodon resembles the pattern predicted for an early mammal: the descending flanges of the frontal and parietal cover the lateral surface of the orbitosphenoid and the palatine forms most of the medial wall of the orbit. In monotremes, the lateral region of the chondrocranium ossifies to form a long presphenoid/orbitosphenoid complex. During the transition from early mammals to extant mammals the height of the alisphenoid decreased drastically, the anterior lamina extended anteriorly to form part of the sidewall while the lateral surface of the orbitosphenoid was exposed by the dorsal withdrawal of the frontal and parietal. By contrast, in multituberculates and therians the lateral edges of the frontals extended further ventrally and the orbitosphenoid was reduced to a smaller orbital exposure below the frontals. In multituberculates the alisphenoid decreased in height, replaced by an anterior extension of the anterior lamina. The palatine withdrew from the orbital wall, replaced by a dorsally directed expansion of the maxilla. Extant therians have lost the anterior lamina. The inferior edges of the frontal followed the further ventral migration of the orbitosphenoid. The alisphenoid and parietal form most of the braincase sidewall.


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Trevor H. Worthy, Vanesa L. De Pietri, and R. Paul Scofield (2017)
Recent advances in avian palaeobiology in New Zealand with implications for understanding New Zealand’s geological, climatic and evolutionary histories. 
New Zealand Journal of Zoology (advance online publication)
doi: http://dx.doi.org/10.1080/03014223.2017.1307235
http://www.tandfonline.com/doi/abs/10.1080/03014223.2017.1307235?journalCode=tnzz20


New Zealand, long recognised as a land where birds dominate the terrestrial vertebrate biota, lacked an informative fossil record for the non-marine pre-Pleistocene avifauna until the twenty-first century. Here we review recent research that alters the known diversity of the fossil Paleogene–Neogene birds and our understanding of the origin of New Zealand’s recent or modern biota. Since 2010, there has been a 50% increase in the number of described fossil bird species (now 45) for the pre-Quaternary period. Many represent higher taxa that are new or listed for New Zealand for the first time, including 12 genera (35 total), nine family-level taxa (18 total), and seven ordinal taxa. We also review recent multidisciplinary research integrating DNA and morphological analyses affecting the taxonomic diversity of the Quaternary avifauna and present revised diversity metrics. The Holocene avifauna contained 217 indigenous breeding species (67% endemic) of which 54 (25%) are extinct.


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Free pdf:

Andrew S Gale, William J Kennedy, David Martill (2017)

Mosasauroid predation on an ammonite – Pseudaspidoceras – from the Early Turonian of south-eastern Morocco.

Acta Geologica Polonica 67 (1): 31–46

DOI: 10.1515/agp-2017-0003

https://geojournals.pgi.gov.pl/agp/article/view/25689/pdf




A juvenile specimen of the ammonite Pseudaspidoceras from the Early Turonian of the Goulmima area in the Province of Er-Rachida in south-eastern Morocco shows clear evidence of predation by a tooth-bearing vertebrate. Most of the body chamber is missing, as a result of post-burial compactional crushing. The adapertural part of the shell on the left flank of the surviving fragment of body chamber bears six circular punctuations; the right flank four. These are interpreted as the product of a single bite by a mosasauroid, probably a Tethysaurus.