Enchodus

Name Meaning:  Spear Tooth

Geologic Era:  Cretaceous to Paleocene

Location Discovered:  Worldwide

Size:  Up to 1.4 meters (around 4 feet)

Estimated Range:  Worldwide

Extinction Date:  Paleocene

Enchodus was one of the fish that escaped extinction at the K-T event.  It, along with other bony and cartilagenous fishes, became the dominant predators of the world’s oceans, having replaced mosasaurs and plesiosaurs.  The K-T event allowed for greater diversification among the groups that did survive.  Those that fared especially well were fish and mammals. 

One of the popular names for this species is the Saber Toothed Herring, and the tooth and skeleton illustrate how it came by this name.  Our tooth measures over 5 cm long, and is probably one of the large, front fangs that Enchodus possessed.  In life, our specimen probably would have been about 1 meter long.  Teeth aside, Enchodus closely resembles modern fish such as herring and salmon.  In fact, it is more closely related to modern salmon than to other fish. 

In terms of its head, Enchodus looks not unlike modern deep sea fishes, who also often have long, recurved teeth.  This would be an example of convergent evolution.  Convergent evolution is when animals evolve similar traits, but aren’t closely related (see ichthyosaurs and dolphins for another example).

The teeth and streamlined body indicate a swift, agile predator.  When the jaws were closed, the teeth interlocked, and would have been effectively used as a spear or cage for captured prey.  Such prey would have included smaller fishes, who Enchodus probably ambushed from beneath.  The eyes are also proportionally very large, indicating good eyesight.  Enchodus was probably very adept at distinguishing light from dark, which is a beneficial trait is one is hunting from below and looking for the silhouettes of other fish.

Despite its fearsome appearance, Enchodus was by no means an apex predator of its time.  Enchodus remains are often found inside mosasaurs, larger sharks and fish, and even birds.  The one thing truly going against it was size.  There were plenty of animals both before and after the K-T event that dwarfed Enchodus in size.  They would probably fit in the same ecological niche as modern salmon.  Modern salmon will eat smaller organisms, but are preyed upon by larger fish, birds, and bears.

Image Credits:

Full Skeleton:  By MCDinosaurhunter (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Life Reconstruction:  By Creator: Dmitry Bogdanov (dmitrchel@mail.ru) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons