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Rhynchosaur osteohistology shows fast growth + giant Eocene penguin from Antarctica



Ben Creisler
bcreisler@gmail.com


A number of recent non-dino papers that may be of interest:


Fábio Hiratsuka Veiga, Marina Bento Soares, and Juliana Manso Sayão (2014)
Osteohistology of hyperodapedontine rhynchosaurs from the Upper
Triassic of Southern Brazil.
Acta Palaeontologica Polonica (in press)
doi:http://dx.doi.org/10.4202/app.00074.2014
http://app.pan.pl/article/item/app000742014.html


The first osteohistological study focused exclusively on rhynchosaurs
(non-archosauriform archosauromorphs), based on the hyperodapedontines
Teyumbaita sulcognathus and Hyperodapedon sp., from the Upper Triassic
of Southern Brazil, indicates a relatively rapid growth rate in early
ontogeny shown by the fibrolamellar complex, with a change to slow
intermittent growth during late ontogeny represented by
parallel-fibred bone with several growth marks. Contrary to previous
studies, which described a typical non-archosaur reptilian bone tissue
pattern for rhynchosaurs, with growth marks extending across the
entire cortex, we demonstrate that, in both studied taxa, the initial
growth rate was faster in comparison to the later. This suggests that
the ability rapid growth at high rates was already present in basal
non-archosauriform archosauromorphs.

==

Carolina Acosta Hospitaleche (2014)
New giant penguin bones from Antarctica: Systematic and
paleobiological significance.
Comptes Rendus Palevol (advance online publication)
DOI: 10.1016/j.crpv.2014.03.008
http://www.sciencedirect.com/science/article/pii/S163106831400058X

A tarsometatarsus and a fragmented humerus of striking dimensions
recently collected in the Late Eocene locality DPV 13/84 Submeseta
Formation-level 38 Submeseta II-, Seymour (Marambio) Island, Antarctic
Peninsula were both assigned to Palaeeudyptes klekowskii. According to
estimates, the tarsometatarsus would belong to the largest and most
massive penguin described so far. This bird was probably a piscivorous
penguin, with high diving ability for catching prey. Although the
humerus is not an appropriate element for body mass or body length
assessments, it also belonged to a huge penguin.


==


Lorenzo Marchetti, Giuseppe Santi & Marco Avanzini (2014)
The problem of small footprints in paleoichnology: remarks on the
Early Permian ichnotaxon Erpetopus cassinisi , a local species from
Southern Alps (Northern Italy).
Rivista Italiana di Paleontologia e Stratigrafia 120(2)
http://www.rivistaitalianadipaleontologia.it/pub/index.php/contents-1997-2014/79-abstracts/140-abstracts-vol-120-2-2014

Based on well-preserved specimens, and strictly considering the
influence of extramorphological (substrate-related) factors, the use
of modern techniques (computer drawings, 3D acquisitions), permitted a
reliable study on footprints smaller than 20 mm. Footprints of this
size were mostly considered as too small and being affected by a lot
of deformation, thus preventing a substantiated analysis. Our case
study focuses on the Erpetopus/Camunipes dualism. Ichnologists
disagree on the value of a separation of these ichnogenera, and their
discussion appears rather "philosophical" than being conducted by an
accurate analysis and objective data. We restudied the holotype of
Camunipes cassinisi (sp. MBS 319), together with a new specimen from
Southern Alps (sp. MBG 12465) that shows five well-preserved long
trackways, and compared them to selected material, including the
Erpetopus willistoni holotype (sp. UGKU C-8). Results suggest a
synonymy of Camunipes with Erpetopus and the new combination Erpetopus
cassinisi which is distinct from E. willistoni by the following
anatomical features: the pes of E. cassinisi shows higher divarication
angles between digits IV-V (>50°) and I-V (>130°) and a longer and
variably oriented digit V, which is long about as digit II. This has
interesting paleobiogeographical consequences: E. cassinisi was
probably a local ichnospecies of Erpetopus in the Southern Alps.

===


Andrea Tintori, Jian-Donghuang, Da-Yong Jiang, Zuo-Yu Sun, Ryosuke
Motani & Guanbao Chen (2014)
A new Saurichthys (Actinopterygii) from the Spathian (Early Triassic)
of Chaohu (Anhui Province, China).
Rivista Italiana di Paleontologia e Stratigrafia 120(2)
http://www.rivistaitalianadipaleontologia.it/pub/index.php/contents-1997-2014/79-abstracts/140-abstracts-vol-120-2-2014



A new species of Saurichthys, S. majiashanensis , is described. It
comes from a series of marine vertebrate-bearing beds of the upper
member of the Nanlinghu Formation outcropping in the large quarry at
the top of Majiashan (Majia Hill) near Chaohu (Hefei City, Anhui
Province, China). Its age is Middle Spathian (Olenekian, Early
Triassic). This new species deeply differs from the several
pre-Spathian species of Saurichthys mainly for having only two
longitudinal scale rows together with a reduced grid-like structure
for the neural elements in the vertebral column. Further derived
characters are in the endoskeleton of the dorsal and anal fin, where
radials articulate only to anterior lepidotrichia, the posterior ones
being supported by the first scale from the caudal pedicle mid-dorsal
and mid-ventral rows, deeply imbedded in the body. In addition, the
haemal spines of the caudal region are much enlarged and reversed,
with their distal parts pointing forwards. Though the skull is
lacking, postcranial characters are enough to justify the erection of
a new species. This new Saurichthys species, together with other few
actinopterygians, can be considered as the oldest assemblage of the
Triassic Middle Fish Fauna, which bloomed probably in the early
Anisian and widespread especially all over the Tethys for the Middle
Triassic and at least the Carnian in the Late Triassic. This new fish
assemblage, together with some of the oldest marine reptiles, is
considered as the beginning of the actual Triassic recovery among
marine vertebrates.

==


Bryony A. Caswell & Angela L. Coe (2014)
The impact of anoxia on pelagic macrofauna during the Toarcian Oceanic
Anoxic Event (Early Jurassic).
Proceedings of the Geologists' Association (advance online publication)
DOI: 10.1016/j.pgeola.2014.06.001
http://www.sciencedirect.com/science/article/pii/S001678781400042X

Extreme environmental change during the Toarcian Oceanic Anoxic Event
had widespread impacts on marine biota. This study provides new
evidence, from the Yorkshire coast sections, UK, that the event was
associated with periods of elevated fish and ammonite mortality. Using
a synthesis of pelagic macrofaunal changes, benthic macrofaunal data
and geochemical proxies we show that there are stratigraphical
correlations between: (1) pelagic macrofaunal ranges and abundance,
(2) benthic macrofaunal abundance, and (3) geochemical proxies that
indicate deoxygenation. We identify eight stratigraphical intervals of
differing character. Results suggest two major phases of relatively
persistent deoxygenation with photic zone euxinia. The
cyclostratigraphic timescale indicates that each phase lasted at least
tens of thousands of years. Belemnite migration during the event
probably resulted from increased seawater temperatures and low food
supply similar to that observed for many marine taxa, including squid,
within the present-day oceans.