Cambrian seas - Wheeler Shale

Wheeler Shale, Middle Cambrian of what is now Utah, USA. In this first period of the Phanerozoic Eon, the diversity of life on Earth exploded and brought creatures with curious and unusual forms, some very different ones from what we are used to see today.

The largest animal on the scene (with "giants" 30cm long) is a Peytoia nathorsti, a relative of the famous Anomalocaris and, just like it, the apex predator of the environment. Its presence scares some conodonts Hertzina sp. in the upper right corner, although these are not its preferred meal (Peytoia would prefer larger, benthic prey).

In the lower right, the cyanobacteria Morania forms a mat that covers the bottom and attracts some Wiwaxia corrugata, close relatives of molluscs (perhaps molluscs themselves) with an armored and spiky appearance. A juvenile individual appears in the scene, still devoid of the "spikes". Also on the mat and on the nearby rocks are a pair of the trilobites Asaphiscus wheeleri and some Naraoia compacta, close relatives but not true trilobites. Another trilobite, the very abundant Elrathia kingii, appears in the foreground, lower left corner, and with several individuals scattered on the rocks further away. On the sandy bottom, the burrowing priapulid-like worm Ottoia proliferates is seen.

Other curious organisms are the sponges, represented here by Choia carteri, with the appearance of a thorny disk and suspended from the bottom by stalks, Chancelloria pentactata with its cactus appearance and the smaller sponge Diagoniella sp. In addition to sponges, there are also some Sphenoecium wheeleri (foreground and upper rocks), which are Pterobranchia (colonial invertebrates) that form tube constructions, and the alga Marpolia sp., which covers some rocks with its clumps of filaments.

The illustration is the first produced for a project by João Macêdo, which will tell stories about the life on Earth throughout the periods of the Phanerozoic Eon. Check out his project:
https://sites.google.com/view/talesfromthephanerozoic/introduction