A remarkable group of thick‐headed Triassic Period archosauromorphs with a wide, possibly Pangean distribution

2021 ◽  
Author(s):  
Sterling J. Nesbitt ◽  
Michelle R. Stocker ◽  
Sankar Chatterjee ◽  
John R. Horner ◽  
Mark B. Goodwin
Keyword(s):  
Triassic Period

Molecular phylogeny and divergence time estimates of Penaeid Shrimp Lineages (Decapoda: Penaeidae)

Zootaxa ◽  
2009 ◽  
Vol 2107 (1) ◽  
pp. 41-52 ◽  
Author(s):  
CAROLINA M VOLOCH ◽  
PABLO R FREIRE ◽  
CLAUDIA A M RUSSO
Keyword(s):  
Fossil Record ◽  
Divergence Time ◽  
Penaeid Shrimp ◽  
Divergence Time Estimates ◽  
Time Estimates ◽  
Global Clock ◽  
Late Tertiary ◽  
The Family ◽  
Molecular Studies ◽  
Triassic Period

Fossil record of penaeids indicates that the family exists since the Triassic period, but extant genera appeared only recently in Tertiary strata. Molecular based divergence time estimates on the matter of penaeid radiation were never properly addressed, due to shortcomings of the global molecular clock assumptions. Here, we studied the diversification patterns of the family, uncovering, more specifically, a correlation between fossil and extant Penaeid fauna. For this, we have used a Bayesian framework that does not assume a global clock. Our results suggest that Penaeid genera originated between 20 million years ago and 43 million years ago, much earlier than expected by previous molecular studies. Altogether, these results promptly discard late Tertiary or even Quaternary hypotheses that presumed a major glaciations influence on the diversification patterns of the family.

scholarly journals An unusual archosauriform tooth increases known tetrapod diversity in the lower Chinle Formation (Late Triassic) of southeastern Utah

2015 ◽  
Author(s):  
Andres Lopez ◽  
Isabella St. Aude ◽  
David Alderete ◽  
David Alvarez ◽  
Hannah Aultman ◽  
...  
Keyword(s):  
Late Triassic ◽  
Chinle Formation ◽  
Triassic Period ◽  
Using Data

An unusual tetrapod tooth was discovered in the Late Triassic Chinle Formation of southeastern Utah. The tooth was originally thought to belong to Revueltosaurus but further investigations have rejected that hypothesis. In this paper we compare MNA V10668 to other known fossil teeth found in the Chinle Formation and identify the least inclusive clade it may belongs to. Using data found in other publications and pictures of other teeth, we compare this specimen to other Triassic dental taxa. MNA V10668 shares some similarities with Crosbysaurus, Tecovasaurus, and several other named taxa but possesses unique characteristics not found in other diapsid teeth. We conclude that it is most likely an archosauromorph and probably an archosauriform. This increases the known diversity of tetrapods from the Chinle Formation and represents the first tooth morphotype completely unique to Utah in the Late Triassic Period.

scholarly journals Anomalously high variation in postnatal development is ancestral for dinosaurs but lost in birds

2016 ◽  
Vol 113 (51) ◽  
pp. 14757-14762 ◽  
Author(s):  
Christopher T. Griffin ◽  
Sterling J. Nesbitt
Keyword(s):  
Postnatal Development ◽  
Intraspecific Variation ◽  
Early Jurassic ◽  
Late Triassic ◽  
Growth Trajectories ◽  
Low Levels ◽  
Triassic Period ◽  
Rates Of Growth

Compared with all other living reptiles, birds grow extremely fast and possess unusually low levels of intraspecific variation during postnatal development. It is now clear that birds inherited their high rates of growth from their dinosaurian ancestors, but the origin of the avian condition of low variation during development is poorly constrained. The most well-understood growth trajectories of later Mesozoic theropods (e.g.,Tyrannosaurus,Allosaurus) show similarly low variation to birds, contrasting with higher variation in extant crocodylians. Here, we show that deep within Dinosauria, among the earliest-diverging dinosaurs, anomalously high intraspecific variation is widespread but then is lost in more derived theropods. This style of development is ancestral for dinosaurs and their closest relatives, and, surprisingly, this level of variation is far higher than in living crocodylians. Among early dinosaurs, this variation is widespread across Pangaea in the Triassic and Early Jurassic, and among early-diverging theropods (ceratosaurs), this variation is maintained for 165 million years to the end of the Cretaceous. Because the Late Triassic environment across Pangaea was volatile and heterogeneous, this variation may have contributed to the rise of dinosaurian dominance through the end of the Triassic Period.

scholarly journals Characterisation of a solvent-tolerant haloarchaeal (R)-selective transaminase isolated from a Triassic period salt mine

2019 ◽  
Vol 103 (14) ◽  
pp. 5727-5737 ◽  
Author(s):  
Stephen A. Kelly ◽  
Damian J. Magill ◽  
Julianne Megaw ◽  
Timofey Skvortsov ◽  
Thorsten Allers ◽  
...  
Keyword(s):  
Salt Mine ◽  
Triassic Period ◽  
Solvent Tolerant

Building a structural image in the Elward area in the Syrian Euphrates Graben using 3D seismic data

2016 ◽  
Vol 4 (1) ◽  
pp. T63-T77
Author(s):  
Rabah Shaheen ◽  
Riad Taifour ◽  
Mohammad Alsouki
Keyword(s):  
Cross Sections ◽  
Seismic Data ◽  
Upper Cretaceous ◽  
Structural Deformation ◽  
Late Triassic ◽  
3D Seismic ◽  
Restoration Techniques ◽  
Structural Image ◽  
Triassic Period ◽  
3D Seismic Data

By generating fault maps, isochron maps, and applying restoration techniques to 3D seismic data acquired over the Elward area of Syria, we have built a suite of cross sections that represent the tectonic evolution of the area. Fault maps and time structure maps reveal structural deformation, whereas isochron maps define areas of fault-controlled depocenters. Seismic attributes delineate fluvial channels formed during the Late Triassic period. The main rift phase in the study area is the Upper Cretaceous (Coniacian). Our analysis explained the absence of the Judea and the upper part of the Rutbah Formations from the stratigraphic column of the Elward north field.

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