Exquisite Triassic Fossil Fish Nodule From Madagascar

Name: Australosomus merlei

Phylum Chordata; Class Actinopterygii; Subclass Chondrostei; Order Pholidoformes; Family Pholidopleuridae

Geological Time: Lower Triassic (~240 m.y.a.)

Size: 60 mm long

Fossil Site: Ambilobe, Madagascar

Triassic Fossil FishThis is a positive negative specimen nodule from the early Triassic of Madagascar containing most of a very detailed fish known as Australosomus merlei. Australosomus is thought to have lain in wait, then shot forward toTriassic Fossil Fish catch its prey. It has a free maxilla, something that in later fish could swing forward as the fish opened its mouth, forming a “slurp gun” Specimens such as this are rare and few are so complete. Notice the teeth, delicate fin rays and the regular pattern of the large scales. This one is missing only the distal portion of the caudal fin, a fine example of a genus that went extinct during the middle Triassic. An interesting aspect of these nodules is that the two haves are not typically part/counterparts, but each retains the impressions of the opposite sides of the fish.

click fossil pictures to enlarge

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