[dinosaur] Fernando Novas + Mexican dinosaurs exhibit + new Diario de los Dinosaurios + more

I've been debating whether I should post these refs. If I post them as "news items" instead of as formal postings of new papers, maybe I can avoid possibly being seenÂ as endorsing "morphogenetic field" theories (or the giant Triassic "kraken" that used ichthyosaur vertebrae to create art).Â So, for the curious....

Mark A.S. McMenamin (2018)

Deep Time Analysis: A Coherent View of the History of Life

DOI: https://doi.org/10.1007/978-3-319-74256-4

https://link.springer.com/book/10.1007/978-3-319-74256-4#toc

Mark A. S. McMenamin (2018)

Barasaurus Squamation.

in Deep Time Analysis:Â 159-204

DOI:Â https://doi.org/10.1007/978-3-319-74256-4_8

https://link.springer.com/chapter/10.1007/978-3-319-74256-4_8

New specimens of the procolophonoid parareptile Barasaurus from the Permo-Triassic Sakamena Group of Madagascar show skin preservation in the form of scale patches. Based on its appendicular skeletal anatomy, Barasaurus was an aquatic form, the only known aquatic procolophonoid. Its squamation consisting of large (up to 4 mm greatest dimension on an animal approximately 30 cm in length), skink-like ventral scales suggest that this ventral scale configuration was well suited for existence in an aquatic habitat. The Barasaurus lifestyle was comparable to that of the crab-eating modern Madagascan skink (Amphiglossus astrolabi). Although they had the potential to do so since they survived the Permo-Triassic mass extinction, barasaurian procolophonoids did not diversify into a major group of Mesozoic Marine tetrapods.

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Mark A. S. McMenamin (2018)

Tetrapteryx.

in Deep Time Analysis:Â 205-214

DOI: https://doi.org/10.1007/978-3-319-74256-4_9

https://link.springer.com/chapter/10.1007/978-3-319-74256-4_9

The primary feathers on the hind limbs of Microraptor give us an important clue about the nature of the 'feather scleritome'. The Microraptor morphogenetic field hosts four curved projections representing the animalâs limbs. This is the case for all tetrapods. Like the bot fly larva, but in reverse, the extra sclerites/enations (maggot spines versus primary feather primordia, respectively) are on the trailing edge of a transverse bulge of the body rather than the leading edge of the bulge (anterior edge larval segment versus posterior edge of limb, respectively). Birds surely passed through an ancestral stage (Tetrapteryx) that developed the hind limbs as wing-like structures and, in accord with Goetheâs Law of Compensation, feathering on the hind limbs was reduced as the lineage relied more and more on their forelimbs for powered flight.

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Mark A. S. McMenamin (2018)

Zealanditherians.

in Deep Time Analysis: 215-237Â

DOI: https://doi.org/10.1007/978-3-319-74256-4_10

https://link.springer.com/chapter/10.1007/978-3-319-74256-4_10

Marsupials first appear in Cretaceous North America, their ancestors having arrived from Asia during an eastward migration of Mesozoic metatherians. By the end of the Mesozoic, the North American metatherians had developed into large (over one meter long) animals with a powerful bite force, partly a function of hypertrophied premolars (p3) in some species. The inflated premolar is associated with reappearance of zahnreihen in a Cretaceous metatherian mammal, Didelphodon coyi. The metatherian migration begun in Asia continued through North America, to South America, to Antarctica and on to Australia where marsupials underwent a well known adaptive radiation in 'splendid isolation. Until recently it was thought that terrestrial mammaliaforms never reached New Zealand, as New Zealand had tectonically rifted away from Antarctica at 82 million years ago, supposedly before marsupials had reached Antarctica. Recent discoveries from limited exposures of Miocene strata in New Zealand near Otago show that mammaliaforms had indeed colonized and diversified in New Zealand apart from their ancestors in the rest of the Gondwanan continental diaspora. These zealanditherians inhabited the newly characterized continent Zealandia, and were apparently driven to extinction by habitat loss when most of Zealandia was submerged by the sea.