Monday, October 12, 2015

Prehistoric Times Playset

Thanks to Howard Moody at Vintage Dinosaur Pictures.

Friday, October 09, 2015

The Early Flight Ability of Birds

Soft-tissue and dermal arrangement in the wing of an Early Cretaceous bird: Implications for the evolution of avian flight. 2015.

Hawkman © DC Comics
Some of the most ancient birds were capable of performing aerodynamic feats in a manner similar to many living birds based on the study of a well-preserved right wing of a 125-million-year-old bird from central Spain.
This new fossil preserves not only the articulated bones of the forelimb but also abundant remains of the plumage and of the soft-tissues of the wing. It matches anatomically with a complex network of ligaments, muscles and tendons present in modern-day birds. This network ensures the position and controls the fine adjustments of the wing's main feathers, allowing living birds to fly efficiently and master the sky. PR

King Kong vs Pteranodon

Thursday, October 08, 2015

48-million-year-old horse-like fetus from Messel, Germany

Description of a Well Preserved Fetus of the European Eocene Equoid Eurohippus messelensis. 2015. PLoS ONE 10(10):e0137985.

Skeleton of a mare of Eurohippus messelensis is shown with fetus (white ellipse). The specimen was discovered and excavated by a team in Frankfurt. Shoulder height ca. ~30 cm; scale = 10 cm. Credit: Franzen et al. Senckenberg Forschungsinstitut Frankfurt, Sven Tränkner

Read more at: Phys Org.

Friday, October 02, 2015

Growth of the Hadrosaurid Maiasaura

Maiasaura, a model organism for extinct vertebrate population biology: a large sample statistical assessment of growth dynamics and survivorship. 2015. Paleobiology

Abstract [edit]: A histological sample of 50 tibiae of the hadrosaurid dinosaur Maiasaura peeblesorum allows predictions of annual growth and ecological interpretations based on more histologic data than any previous large sample study. Tibia length correlates well (R2> 0.9) with diaphyseal circumference, cortical area, and bone wall thickness, thereby allowing longitudinal predictions of annual body size increases based on growth mark circumference measurements.

With an avian level apposition rate of 86.4 μm/day, Maiasaura achieved over half of asymptotic tibia diaphyseal circumference within its first year. Mortality rate for the first year was 89.9% but a seven year period of peak performance followed, when survivorship (mean mortality rate= 12.7%) was highest. During the third year of life, Maiasaura attained 36% (x= 1260 kg) of asymptotic body mass, growth rate was decelerating (18.2 μm/day), cortical vascular orientation changed, and mortality rate briefly increased. These transitions may indicate onset of sexual maturity and corresponding reallocation of resources to reproduction.

Skeletal maturity and senescence occurred after 8 years, at which point the mean mortality rate increased to 44.4%. Compared with Alligator, an extant relative, Maiasaura exhibits rapid cortical increase early in ontogeny, while Alligator cortical growth is much lower and protracted throughout ontogeny.

Congrats to Holly, Liz, Jim and Jack on a great paper!

Wendiceratops PLOS t-shirt

Danielle Dufault's image of our Wendiceratops is now on a t-shirt for PLOS (Public Library of Science), the journal that published the original paper. The shirts will be given away to social media blogger/twitterers at the upcoming SVP conference posting for the journal.