Gyaltsenglossus senis, is a newly described hemichordate from the Burgess Shale. It provides evidence on how the anatomies of the two main groups of hemichordates – enteropneusta and pterobranchia – are related. The enteropneusta and pterobranchia differ in body shape and in ecological function. However, DNA analysis of present day organisms suggests that they are […]
A 506 million year old hemichordate worm with tentacles Read More »
Kylinxia zhangi is a newly described euarthropod with five-eyes. It is was discovered in a Cambrian aged deposit in Chengjiang, China, and was recently described in the journal Nature. Kylinxia looks remarkably like a cross between two Burgess Shale animals, Opabinia regalis and Anomalocaris canadensis. The Burgess Shale is currently dated to 506 million years
Five-eyes!? Kylinxia zhangi, a new Opabinia-like fossil Read More »
Tropical Fossils? The Burgess Shale fossils are found in the Canadian Rockies at a latitude of 51 North. However, the fossilized animals lived and died in the tropics. This change in latitude over time is the result of the slow action of Plate Tectonics. For the last 508 Million years the North America plate has
Tropical Fossils: The Burgess Shale Is Not Alone! Read More »
Cambrian Explosion The early Cambrian period marks one of the most spectacular evolutionary events in the history of life – The Cambrian Explosion. This was an explosion of life. Within ten million years, a very short period geologically, a host of hard-body and soft-body animals appeared in the fossil record. Trilobites, molluscs, chordates, cnidarians, brachiopods and
The Gog Group underlies the Cambrian rocks where the Burgess Shale fossils are found. Those of you not wearing a bathing suit and a life preserver would be ill prepared if you somehow found yourself in Yoho National Park in the Cambrian. Beginning in the Early Cambrian (~541 million years ago), sea levels rose and
The Geology of the Burgess Shale (Part 1): The Gog Group Read More »
The above Cambrian map is from Dr. C. Scotese’s Paleomap project. Note that Laurentia is the Paleo-Continent of North America. In other words, Laurentia is an early version of North America. The outline of present day North America is in white. It may be a little bit hard to recognize because the continent is turned
Would You Rather Live in the Cambrian Than Present-Day? Read More »
Geological time is exceptionally hard to fathom. If you are like me, you probably have difficulty conceiving of a million years. The Earth is currently 4.543 billion years old. While this number is much smaller than the federal debt of most developed nations, it is still enormous. To help comprehend such large numbers we often
The Burgess Shale and its Place in Geological Time Read More »
Until recently, paleontologist have had difficulty deciding where the Habeliida taxa belonged on the tree of life. A recent re-description of the arthropod habelia optata places the Habeliida next to the Chelicerata. Horseshoe crabs, sea spiders, scorpions and spiders are all Chelicerates. Tree of life showing the relationship between Arthropods (Cedric Aria) For more information about the re-description of Habelia optata consult the
Habelia optata – The Cambrian arthropod with a ‘Jacknife’ head Read More »