Theropoda

Jinfengopteryx elegans 2

Anchiornis feathers

Longest theropods

Bee hummingbird (Mellisuga helenae) adult male in flight-cropped

Error creating thumbnail:

Struthio camelus - Etosha 2014 (1)

Mummified precocial bird wings in mid-Cretaceous Burmese amber (2016) fig. 1

Theropoda (Theropods) is a dinosaur clade that is characterized by hollow bones and three-toed limbs. Theropods are predominantly known as carnivorous dinosaurs, including some of the most well-known species such as Tyrannosaurus rex, Velociraptor, and Spinosaurus. They first appeared during the Late Triassic period and include both extinct species as well as their modern descendants, the birds.

Characteristics

Theropods were primarily carnivorous, although a number of groups evolved to have omnivorous or herbivorous diets. They were bipedal, with the hind limbs used for locomotion and the forelimbs, which varied greatly in size among species, used for grasping, holding, and manipulating objects. Their feet had three main toes, and their bones were hollow, contributing to a lighter skeleton that enhanced their agility and speed.

Evolution

The earliest theropods appeared in the Late Triassic, approximately 230 million years ago. Over time, they diversified into a wide range of sizes and shapes, from the small, feathered Microraptor to the massive, towering Tyrannosaurus rex. The discovery of feathered theropods in the Jurassic period deposits of China provided strong evidence for the evolutionary link between theropods and modern birds, with many scientists now considering birds to be living theropods.

Classification

Theropoda is divided into several subgroups, including the Coelurosauria, which encompasses birds and their closest dinosaur relatives, and the Carnosauria, which includes larger predators like Allosaurus. Another important group is the Maniraptora, known for their advanced grasping abilities and which includes both birds and their closest non-avian relatives.

Significance in Paleontology

Theropods have been central to the study of dinosaur evolution and behavior. Their well-preserved fossils, including evidence of feathers, nesting behaviors, and social interactions, have provided invaluable insights into the life of dinosaurs. The transition from theropod dinosaurs to birds has been particularly well-documented, offering a detailed case study of evolutionary processes.

In Popular Culture

Theropods have captured the public imagination and have been featured prominently in books, movies, and television shows. The Jurassic Park franchise, in particular, has played a significant role in popularizing theropods, although it has also been criticized for inaccuracies in its portrayal of these dinosaurs.