Fossils of the Cambrian Explosion from Utah
Fossil Sites
 

Cambrian Explosion Fossils of Utah - America's Burgess Shale

Related interest:
The Cambrian Explosion
House Range Lagerstätte Fossil Site
Fossils of Chengjiang, China
Fossils of the Pioche Formation
Burgess Shale Fossils
Utah Trilobites

 

The Burgess Shale of Canada and Chengjiang, in Yunnan Province, China are the best known Lagerstatte of Cambrian time Both sites have a great diversity of benthic or burrowing creatures. Less well known is that the western state of Utah has similar fauna of the Cambrian Explosion. Interestingly, some scientists believe that a larger number of species are found in the Weeks, Wheeler and Marjum Formations within the House Range in Utah than in the Burgess Shale, though the fossils are far less abundant and not as well preserved. Even fewer are collected simply because collectors usual do not recognize them as fossils.

During the Cambrian, what is now Utah was part of the continent of Laurentia that now encompasses what is now North America. Cambrian outcrops bearing well preserved biota of the Cambrian Explosion are found in Utah, Western Canada and California, among others. Warm shallow seas covered Utah itself, a perfect environment for fine sediments to rapidly bury a diverse and exploding faunal assemblage of marine organisms.

The Middle Cambrian Wheeler, Marjum and Weeks Formations are exposed within the House Range west of Delta, Utah. Both formations are famous for their trilobites and other shelly fossils, but also contain a rich diversity of fossils of soft-bodied animals of the Cambrian Explosion, some of which from these and other Utah locations are shown below.

Utah Cambrian Cambrian Explosion Fossils

Brachiocaris pretiosa
Lamellipedia
Emeraldella
Brachiocaris pretiosa
Phyllocarid

Rare Arthropod
House Range
Emeraldella
Enigmatic Early Arthropod
Weeks Formation
Emeraldella
Enigmatic Early Arthropod
Weeks Formation
Pseudoarctolepis sharpi
Wiwaxia

Undescribed Aglaspid
Soft Bodied Arthropod
Weeks Formation

Hallucigenia
Enigmatic Cambrian Soft Bodied Animal
Spence Shale
Anomalocaris limb
Cambrian Soft Body Predator
Marjum Formation
Emeraldella
Problematic Soft-Bodied Animal
Marjum Formation
Selkirkia
with Gut Trace and Proboscis
Marjum Formation
Annelid
Predator Worm Fossil
Marjum Formation
Crumillospongia Sponge Fossil

Yuknessia sp., fossil algae
Wheeler Shale

Choia utahensis Sponge Fossils
Naraoia Soft Bodied Arthropod
Crumillospongia Sponge Fossils
Naraoia

Naraoia sp
Soft Bodied Arthropod
Showing Digestive Track
Marjum Formation

Naraoia sp
"soft-bodied arthropod"
Marjum Formation
Ctenocystis Echinoderms
Annelid Worm fossil
Stromatolites
Marjum Formation
Ctenocystis Echinoderms
Marjum Formation
Possible Annelid Worm
Wheeler Shale
Beckwithia typa
Weeks Formation
Altiocculus harrisi Alokistocarid Trilobite
with Anomalocaris
Bites
Wheeler Shale