Asaphiscus wheeleri
 


scale in cms

CLASS - Trilobita
ORDER - Ptychopariida
FAMILY - Asaphiscidae
GENUS/SPECIES - Asaphiscus wheeleri

ROCK UNIT - Wheeler Shale

AGE - Middle Cambrian (525 million years old)

LOCALITY - Antelope Springs, Utah, USA

The head on this trilobite might looks unusual because only part of it remains. The two side portions, called "free cheeks," are missing. They apparently broke away when the animal shed it skeleton in order to grow a larger one. This process is called molting, and is shared by all arthropods.

All arthropods (including trilobites) live inside their skeleton, so they must shed it to grow larger. When somebody eats "soft-shell crab" at a seafood restaurant, they're eating a crab that has just molted and is beginning to build a new, hard, outer shell. Some trilobites may have molted as many as 30 times in order to reach maximum adult size.

PRI 42111

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Asaphiscus wheeleri

PRI 42111


scale in cms

CLASS - Trilobita
ORDER - Ptychopariida
FAMILY - Asaphiscidae
GENUS/SPECIES - Asaphiscus wheeleri

ROCK UNIT - Wheeler Shale

AGE - Middle Cambrian (525 million years old)

LOCALITY - Antelope Springs, Utah, USA

The head on this trilobite might looks unusual because only part of it remains. The two side portions, called "free cheeks," are missing. They apparently broke away when the animal shed it skeleton in order to grow a larger one. This process is called molting, and is shared by all arthropods.

All arthropods (including trilobites) live inside their skeleton, so they must shed it to grow larger. When somebody eats "soft-shell crab" at a seafood restaurant, they're eating a crab that has just molted and is beginning to build a new, hard, outer shell. Some trilobites may have molted as many as 30 times in order to reach maximum adult size.