Dinosaur phylogeny - major changes (1 Viewer)

Press release and Nature abstract about some major new findings on dinosaur phylogeny from the Natural History Museum (London) that might be of interest - if verified, it'll affect the origin of birds.

Also of dinosaur interest, some sauropod footprints recently found in Western Australia, each footprint 170 cm long - the previous largest known was 106 cm :eek!: :eek!: :eek!: :eek!: :eek!:

Ben Creisler march 21 2017 already wrote:

A new paper:

Matthew G. Baron, David B. Norman & Paul M. Barrett (2017)

A new hypothesis of dinosaur relationships and early dinosaur evolution.

Nature 543: 501–506

doi:10.1038/nature21700

http://www.nature.com/nature/journal/v543/n7646/full/nature21700.html

Free pdf of supp:

http://www.nature.com/nature/journal/v543/n7646/extref/nature21700-s1.pdf

For 130 years, dinosaurs have been divided into two distinct clades—Ornithischia and Saurischia. Here we present a hypothesis for the phylogenetic relationships of the major dinosaurian groups that challenges the current consensus concerning early dinosaur evolution and highlights problematic aspects of current cladistic definitions. Our study has found a sister-group relationship between Ornithischia and Theropoda (united in the new clade Ornithoscelida), with Sauropodomorpha and Herrerasauridae (as the redefined Saurischia) forming its monophyletic outgroup. This new tree topology requires redefinition and rediagnosis of Dinosauria and the subsidiary dinosaurian clades. In addition, it forces re-evaluations of early dinosaur cladogenesis and character evolution, suggests that hypercarnivory was acquired independently in herrerasaurids and theropods, and offers an explanation for many of the anatomical features previously regarded as notable convergences between theropods and early ornithischians.

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Kevin Padian (2017)

Dividing the dinosaurs.

Nature 543: 494–495

doi:10.1038/543494a

http://www.nature.com/nature/journal/v543/n7646/full/543494a.html

The standard dinosaur evolutionary tree has two key branches: the 'bird-hipped' Ornithischia and the 'reptile-hipped' Saurischia. A revised tree challenges many ideas about the relationships between dinosaur groups. See Article p.501

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News:

http://www.nature.com/news/dinosaur-family-tree-poised-for-colossal-shake-up-1.21681

https://www.theguardian.com/science...ical-shakeup-of-dinosaur-family-tree-saltopus

https://www.newscientist.com/articl...-have-been-omnivores-in-the-north-hemisphere/

https://phys.org/news/2017-03-roots-dinosaur-family-tree.html

https://www.theatlantic.com/science...ldhood-shattered-what-is-real-anymore/520338/

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The paper is widely discussed on the Dinosaur Mailing List:

http://dml.cmnh.org/2017Mar/
◦[dinosaur] Dinosauria reclassification joins Ornithischia and Theropoda in Ornithoscelida

Enjoy,

Fred

Nutcracker wrote: "if verified, it'll affect the origin of birds."

I don't believe it will have a massive effect on how we think about the evolution of birds as they will still have been evolved from Theropods. Perhaps the ancesters of Theropods will turn out to be other animals than we think now.

Fred

Nutcracker said:

Also of dinosaur interest, some sauropod footprints recently found in Western Australia, each footprint 170 cm long - the previous largest known was 106 cm :eek!: :eek!: :eek!: :eek!: :eek!:

Click to expand...

I guess the huge size may be at least partially explained by the type of sediment they were left in (wet sand)? Needless to say, a 1.7 m long footprint doesn't mean a 1.7m foot... Huge, nevertheless...