Giant dinosaurs hatched with adult-like proportions
Analysis of a new dinosaur fossil suggests that the largest species ever known to walk the Earth was born with adult-like proportions, perhaps allowing it to be more independent than some other species of dinosaur.
Analysis of the new fossil by Kristina Curry-Rogers et al. suggests that the youngster they studied, who died (likely from starvation) between the age of 39 and 77 days, weighed roughly 3.4 kilograms (kg) when it hatched.
|UA 9998, a Rapetosaurus perinate, would have stood only knee-high. In comparison, |
an adult Rapetosaurus femur is about the same length as an averaged-sized woman
[Credit: Raul Martin and Kristina Curry Rogers]
The researchers used bone histology and x-ray computed tomography to understand its growth pattern. Based on the compactness of its bones, the authors say that this dinosaur's limbs likely remained similar in shape throughout its life.
|Thin-sections of limb bones reveal patterns of blood supply, degree of remodeling, |
and calcified cartilage growth plates that signal fast-growth and precocity
for baby Rapetosaurus [Credit: K. Curry Rogers, M. Whitney,
M. D'Emic, and B. Bagley]
Therefore, the authors propose that R. krausei infants may have been relatively independent after birth, compared to other species.
The study has been published in the journal Science.
Source: American Association for the Advancement of Science [April 21, 2016]