1. Education
You can opt-out at any time. Please refer to our privacy policy for contact information.




Astraspis (Wikimedia Commons)


Astraspis (Greek for "star shield"); pronounced as-TRASS-pis


Shores of North America

Historical Period:

Late Ordovocian (450-440 million years ago)

Size and Weight:

About 6 inches long and a few ounces


Small marine organisms

Distinguishing Characteristics:

Small size; lack of fins; thick plates on head


About Astraspis:

Like other prehistoric fish of the Ordovician period--the first true vertebrates to appear on earth--Astraspis looked like a giant tadpole, with an oversized head, flat body, wriggling tail and lack of fins. However, Astraspis seems to have been better-armored than its contemporaries, with distinctive plates along its head, and its eyes were set on either side of its skull rather than directly in front. This ancient creature's name, Greek for "star shield," derives from the characteristic shape of the tough proteins that composed its armored plates.

  1. About.com
  2. Education
  3. Dinosaurs
  4. Prehistoric Animals
  5. Tetrapods and Amphibians A to Z
  6. Astraspis

©2014 About.com. All rights reserved.