Troodontids Facts for Kids

Quick facts for kids Troodontids Temporal range: Late Jurassic–Late Cretaceous, 130–66Ma PreЄ Є O S D C P T J K Pg N

Mounted skeletal cast of an unnamed Alaskan troodontid, Perot Museum
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Clade:	Eumaniraptora
Family:	†Troodontidae Gilmore, 1924
Type species
Troodon formosus Leidy, 1856
Subgroups
†Albertavenator †Almas †Archaeornithoides? †Geminiraptor †Jianianhualong †Jinfengopteryx †Koparion? †Liaoningvenator †Paronychodon? †Sinornithoides †Talos †Tochisaurus †Xixiasaurus †Sinovenatorinae †Troodontinae
Synonyms
Saurornithoididae Barsbold, 1974

Troodontids were a group of dinosaurs that looked a lot like birds. They belonged to a family called theropods, which means "beast-footed." These dinosaurs lived mainly in places like Mongolia, China, and North America.

The very first piece of a troodontid ever found was just a single tooth. It was discovered in central Montana in 1855 by a person named Ferdinand Hayden. For a long time, scientists only found small, broken pieces of troodontid fossils.

But recently, much more complete fossils have been found. These include full skeletons, some even with feathers! Scientists have also found eggs and even embryos (baby dinosaurs still inside their eggs). They've also found complete young troodontids. In 1994, a fossil of an adult Troodon was found sitting on a nest with eight eggs. This was a very exciting discovery!

What Made Them Special?
Their Family Tree
Images for kids
See also

What Made Them Special?

Troodontids had some unique features. They had relatively large brains for dinosaurs, which suggests they were quite smart. Their skulls had many air pockets, making them lighter.

One cool thing about them was their second toe claw. It was like a retractable knife! They could pull it in, just like a cat's claws. They also had many teeth. The number of teeth varied between different types of troodontids. For example, Saurornithoides mongoliensis had 96 teeth, while Troodon had up to 120 teeth.

Replica skull of a troodontid, SPV 300/45.

Their Family Tree

Scientists study the bones of these ancient animals to understand how they are related. The earliest troodontids, like Sinovenator, show amazing similarities to Archaeopteryx and other early dromaeosaurids. This tells us they are all part of the same big family tree, a group called Paraves. This group includes birds and their closest dinosaur relatives.

Here are some of the known types of troodontids: