Osteohistological description of ostrich and emu long bones, with comments on markers of growth.

Ostriches and emus are among the largest extant birds and are frequently used as modern analogs for the growth dynamics of non-avian theropod dinosaurs. These ratites quickly reach adult size in under 1 year, and as such do not typically exhibit annually deposited growth marks. Growth marks, commonly classified as annuli or lines of arrested growth (LAGs), represent reduced or halted osteogenesis, respectively, and their presence demonstrates varying degrees of developmental plasticity.

Growing up : Osteohistology refutes the pygmy "" and supports ontogenetic niche partitioning in juvenile .

Despite its iconic status as the king of dinosaurs, biology is incompletely understood. Here, we examine femur and tibia bone microstructure from two half-grown specimens, permitting the assessments of age, growth rate, and maturity necessary for investigating the early life history of this giant theropod. Osteohistology reveals these were immature individuals 13 to 15 years of age, exhibiting growth rates similar to extant birds and mammals, and that annual growth was dependent on resource abundance.

A new fossil assemblage shows that large angiosperm trees grew in North America by the Turonian (Late Cretaceous).

The diversification of flowering plants and marked turnover in vertebrate faunas during the mid-Cretaceous transformed terrestrial communities, but the transition is obscured by reduced terrestrial deposition attributable to high sea levels. We report a new fossil assemblage from multiple localities in the Upper Cretaceous Ferron Sandstone Member of the Mancos Shale Formation in Utah. The fossils date to the Turonian, a severely underrepresented interval in the terrestrial fossil record of North America.