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Small theropod eggs from Japan + Ceratosaurus dismantled + dinosaur origin date + more

Ben Creisler

Some recent items:

Small theropod paravian or bird eggs found in Japan



Dismantling Ceratosaurus skeleton at Smithsonian



A commentary to the article:  The precise temporal calibration of
dinosaur origins.





Hans-Dieter Sues (2016)
Dating the origin of dinosaurs.
Proceedings of the National Academy of Sciences (advance online publication)


The Triassic In 1834, the salt-mining expert Friedrich von Alberti
applied the name “Trias” to a succession of sedimentary rocks in
Germany, which (from oldest to youngest) are the Buntsandstein
(“colored sandstone”), Muschelkalk (“clam limestone”), and Keuper
(derived from a word for the characteristic marls of this unit). The
Buntsandstein and Keuper each comprise predominantly continental
siliciclastic strata, whereas the Muschelkalk is made up of carbonates
and evaporites deposited in a shallow epicontinental sea. Alberti’s
threefold rock succession more or less corresponds to the standard
division of the Triassic into Lower, Middle, and Upper Triassic
series. Later researchers used fossils of marine invertebrates to
correlate carbonate units exposed along the northern and southern
flanks of the European Alps with the Triassic strata in the Germanic
Basin. Starting in the late 19th century, geologists, mostly working
in the Austrian Alps, established the global standard marine stages of
the Triassic Period (from oldest to youngest): Scythian, Anisian,
Ladinian, Carnian, Norian, and Rhaetian. The Scythian was later
further divided into the Induan and Olenekian stages.


Recent decades have witnessed a revolution in our understanding of the
diversification of the two principal evolutionary lineages of
archosaurian reptiles, the crocodile line (Pseudosuchia) and the
dinosaur–bird line (Ornithodira) . Current data suggest that these two
lineages had already diverged from each other at the beginning of the
Triassic or perhaps even during the latest Permian. Thus, we could
expect early occurrences of dinosauriforms, and perhaps even
dinosaurs, although none of the numerous reports of pre-Late Triassic
dinosaurs so far has withstood critical scrutiny. The Manda beds of
Tanzania, long considered early Middle Triassic in age, have yielded
skeletal remains of an undisputed dinosauriform (Asilisaurus) and an
enigmatic taxon, Nyasasaurus, which is known only from a fragment of a
remarkably dinosaur-like humerus and some vertebrae. Precise temporal
calibration of the Manda beds and correlative units elsewhere is
critical for testing whether dinosaurs and their closest relatives
have a long but as yet largely unrecorded history or, as suggested by
Marsicano et al. ,dinosaurs appeared and rapidly diversified at middle
to high paleolatitudes in Gondwana at the beginning of the Late


New Machimosaurus rex, with video



Do modern theropods trap birds to eat later?