Tiny T. Rex Babies Resemble Cats, New Fossils Reveal

Paleontologists at the University of Bath in the United Kingdom analyzed rare fossil fragments and determined that juvenile Tyrannosaurus rex were much smaller than previously believed. The research, published in Biology, examined the first known remains of newborn tyrannosaurs discovered within museum collections.

Researchers initially sought smaller adult dinosaurs but identified an extremely porous bone, indicating rapid growth, belonging to a young T. rex. The analysis suggests hatchlings measured around 75 centimeters long and weighed between 1.7 and 2.5 kilograms at birth, significantly less than prior estimates.

Based on these measurements, scientists estimate that a T. rex nest could have contained 20 to 30 eggs. This discovery challenges earlier assumptions about T. rex reproductive strategies and suggests a possible evolutionary transition between reptiles and modern birds regarding parental investment. No T. rex eggs have yet been definitively identified.