MARCH 22, 2019
The ~125 million-year-old Early Cretaceous fossil beds of Los Hoyas, Spain, have long been known for producing thousands of petrified fish and reptiles (Fig. 1). However, researchers have uncovered an extremely rare, nearly complete skeleton of a hatchling bird. Using their own laser imaging technology, Dr. Michael Pittman from the Department of Earth Sciences at the University of Hong Kong and Thomas G Kaye from the Foundation for Scientific Advancement in the U.S. have determined the lifestyle of this ~3cm long hatchling bird by determining the previously unknown feathering preserved in the fossil specimen (Fig. 2).
Chickens and ducks are "precocial," walking and foraging within hours of hatching (Fig. 3). Pigeons and eagles are "altricial," remaining in the nest and attended by their parents. Scientists have one method to determine the type for a given fossil specimen: examining the feathers. When precocial birds hatch, they have developed down feathers and partly developed large feathers, and can keep warm and move around unassisted by parents. "Previous studies searched for but failed to find any hints of feathers on the Los Hoyas hatchling. This meant that its original lifestyle was a mystery," says Dr. Pittman.