This should make somebody in the group happy... :) http://www.bbc.co.uk/nature/18249270 --Mikko
Category Archives: News
Birds have paedomorphic dinosaur skulls
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11146.html
Birds have paedomorphic dinosaur skulls
Bhart-Anjan S. Bhullar, Jesús Marugán-Lobón, Fernando Racimo, Gabe S. Bever, Timothy B. Rowe, Mark A. Norell & Arhat Abzhanov
The interplay of evolution and development has been at the heart of evolutionary theory for more than a century1. Heterochrony—change in the timing or rate of developmental events—has been implicated in the evolution of major vertebrate lineages such as mammals2, including humans1. Birds are the most speciose land vertebrates, with more than 10,000 living species3 representing a bewildering array of ecologies. Their anatomy is radically different from that of other vertebrates. The unique bird skull houses two highly specialized systems: the sophisticated visual and neuromuscular coordination system4, 5 allows flight coordination and exploitation of diverse visual landscapes, and the astonishing variations of the beak enable a wide range of avian lifestyles. Here we use a geometric morphometric approach integrating developmental, neontological and palaeontological data to show that the heterochronic process of paedomorphosis, by which descendants resemble the juveniles of their ancestors, is responsible for several major evolutionary transitions in the origin of birds. We analysed the variability of a series of landmarks on all known theropod dinosaur skull ontogenies as well as outgroups and birds. The first dimension of variability captured ontogeny, indicating a conserved ontogenetic trajectory. The second dimension accounted for phylogenetic change towards more bird-like dinosaurs. Basally branching eumaniraptorans and avialans clustered with embryos of other archosaurs, indicating paedomorphosis. Our results reveal at least four paedomorphic episodes in the history of birds combined with localized peramorphosis (development beyond the adult state of ancestors) in the beak. Paedomorphic enlargement of the eyes and associated brain regions parallels the enlargement of the nasal cavity and olfactory brain in mammals6. This study can be a model for investigations of heterochrony in evolutionary transitions, illuminating the origin of adaptive features and inspiring studies of developmental mechanisms.
– Jacqueline
Greater India Basin hypothesis and a two-stage Cenozoic collision between India and Asia
Cambrian Shutter of Doom Becomes Sucker of Worms
One gene helped human brains become complex
Mini mammoth once roamed Crete
Evolution crafted pint-sized pachyderm on Mediterranean island.
http://www.nature.com/news/mini-mammoth-once-roamed-crete-1.10605#/ref-link-1
Some interesting new papers
Here are a few very recent papers that might be of interest to the club members:
Using paleontological data to assess mammalian community structure: Potential aid in conservation planning
http://www.sciencedirect.com/science/article/pii/S0031018212002234
Analysis of Dental Root Apical Morphology: A New Method for Dietary Reconstructions in Primates
http://onlinelibrary.wiley.com/doi/10.1002/ar.22482/full
New evidence for canine dietary function in Afropithecus turkanensis
http://www.sciencedirect.com/science/article/pii/S0047248412000437
New insight from old bones: stable isotope analysis of fossil mammals
http://www.bioone.org/doi/abs/10.1644/11-MAMM-S-179.1
-Laura
Tropical climate in West Pacific during the Pleistocene
Dear all,
This paper may interest you
http://www.sciencemag.org/content/early/2012/05/02/science.1218340.abstract
Best,
Elodie
Rise of Humans 2 Million Years Ago Doomed Large Carnivores
Locomotive implication of a Pliocene three-toed horse skeleton from Tibet and its paleo-altimetry significance
http://www.pnas.org/content/early/2012/04/17/1201052109.abstract?etoc