answersLogoWhite

0

They became extinct in the mass extinction at the end of the Ordovician Period.

User Avatar

Wiki User

13y ago

What else can I help you with?

Related Questions

When did dinosuars go extinct?

65 Million years ago, in the Cretaceous time period.


What period in which the last ammonites became extinct?

Ammonites went extinct at the end of the Cretaceous Period.


What is a sentence with the word extinct?

Why did the dinosaurs go extinct? Humans will never go extinct!


Relationship between extinct and mass extinction?

Mass extinction is when many animals go extinct within a short period of time caused by the same variables/factors leading to the mass extinction.


When did the pteraspidomorphi go extinct?

Like Rhamphorhynchus and Anurognathus, Pterodactylus became extinct at the end of the Jurassic Period, making room for larger pterosaurs like Ornithocheirus.


Is Argentavis magnificens extinct?

Yes, Argentavis magnificens went extinct in the late Miocene period.


Why did brachiopods go extinct?

Most brachiopods became extinct about 250 million years ago during the P-T Extinction period. Modern day brachiopods do still exist in the form of lingula.


Why did Missouri go extinct?

Missouri is a state - it is not a living thing so it cannot go extinct.


When did wild silk worms go extinct?

They are not extinct...


When did proboscis monkeys go extinct?

they are not extinct yet.


Was Mount Vesuvius extinct?

No, people just think that it was extinct because it had not erupted in a long period of time.


Did the thrinaxodon go extinct during the End Triassic extinction?

Thrinaxodon lived during the Triassic Period. They died out about 245 million years ago, at the end of the Olenekian portion of the Triassic period.