A baby bird fossil no larger than a pinky finger is providing scientists with a grander view of the avian world in the Age of the Dinosaurs. The creature was found in the wetland deposits of the Las Hoyas fossil site of Spain.
To find the trace of any once-living entity from a past geological age requires some level of serendipity and this discovery is no exception – particularly considering its diminutive size.
The prehistoric chick, which dates back to between 250 and 65 million years ago, is nearly complete, with only its feet, most of the hands, and tail tip missing. The skull is also partially crushed. That degree of degradation might not sound promising, but for paleontologists whose work it is to dig up million-year-old creatures from the bogs of time, it is actually remarkably well preserved.
The researchers estimate that the hatchling was a whopping 5 centimeters (2 inches) in length and weighed 85 grams (3 ounces). This makes it one of the smallest avian fossils ever discovered from the Mesozoic Era.
However, what makes this discovery a paleontological treasure is not just its teensy size but the fact that it died soon after birth, when its bones were still in the process of development (ossification). The critter fossilized during a little-seen, yet critical stage in the skeletal formation of a bird.
"The stage of this fossil is important because fossils of baby birds from the Age of Dinosaurs provide key information about the early development of primitive birds and yet, they are extremely rare," co-author Luis Chiappe, from the LA Museum of Natural History, told IFLScience.