Friday, 26 April 2019

CERATIOCARIS, YE KEN

This braw fellow is Ceratiocaris papilio (Salter in Murchison, 1859) a pod Shrimp from the Silurian mudstones of the Kip Burn Formation in the Midland Valley of Scotland. He would have swam in rising seas filled with crinoids, coral reefs, brachiopods, trilobites and new and exotic fish -- some sporting jaws for the first time.

Ceratiocaris is a genus of extinct paleozoic phyllocarid crustacean whose fossils are found in marine strata from the Upper Ordovician through to the Silurian.

They are typified by eight short thoracic segments, seven longer abdominal somites and an elongated pretelson somite. Their carapace is slightly oval shaped; they have many ridges parallel to the ventral margin and possess a horn at the anterior end.

This tidy specimen is from the Silurian mudstones that characterise the Kip Burn Formation with it's dark laminated silty bands. The lower part of the Kip Burn houses the highly fossiliferous ‘Ceratiocaris beds’, that yield the arthropods Ceratiocaris, Dictyocaris, Pterygotus, Slimonia and the fish Birkenia and Thelodus.

The upper part of the formation, the ‘Pterygotus beds’, contain abundant eurypterid fauna together with the brachiopods Lingula and Ceratiocaris. The faunas in the Kip Burn Formation reflect the start of the transition from marine to quasi- or non-marine conditions in the group.

Ceratiocaris are also well known from the Silurian Eramosa Formation of Ontario, Canada (which also has rather nice eurypterids). Photo credit / collection of: York Yuxi Wang and Tianyi Zhang

Joseph H. Collette; David M. Rudkin (2010). "Phyllocarid crustaceans from the Silurian Eramosa Lagerstätte (Ontario, Canada): taxonomy and functional morphology". Journal of Paleontology. 84 (1): 118–127. doi:10.1666/08-174.1.

M. Copeland; T. E. Bolton (1985). Fossils of Ontario part 3: the eurypterids and phyllocarids. Volume 48 of Life Sciences Miscellaneous Publications. Royal Ontario Museum. ISBN 0-88854-314-X.

Thursday, 25 April 2019

SOLAR POWERED: TABANIDAE

Horsefly / Diptera / Tabanidae; Latreille, 1802
Horseflies are true flies in the family Tabanidae, order Diptera. They are quite large as flies go and adept little aviators. If you've had the pleasure you'd recall meeting them as they have a nasty bite when they do.

It's the female horseflies that do the chomping, preferring livestock and the occasional human as they hike or enjoy the great outdoors.

Horseflies are sun lovers, they are out in force on nice sunny days and set a healthy bedtime as they become inactive and rest when the sun goes down.

Wednesday, 24 April 2019

VICTORASPIS LONGICORNUALIS

This lovely specimen is an armoured agnatha jawless bony fish, Victoraspis longicornualis, from Lower Devonian deposits of Podolia, Ukraine. The specimen shows both the positive and negative of the fossil in high relief.

Victoraspis longicornualis was named by Anders Carlsson and Henning Bloom back in 2008. The new osteostracan genus and species were described based on material from Rakovets' present-day Ukraine. This new taxon shares characteristics with the two genera Stensiopelta (Denison, 1951) and Zychaspis (Javier, 1985).

Agnatha is a superclass of vertebrates. This fellow looks quite different from our modern Agnatha, which include lamprey and hagfish. Ironically, hagfish are vertebrates who do not have vertebrae. Sometime in their evolution they lost them as they adapted to their environment. Photo: Fossilero Fisherman

Tuesday, 23 April 2019

JOHN DAY FOSSIL BEDS

More than a 100 groups of mammals and a wide variety of plants have been found in the early Miocene, 39-19 million year old, John Day Formation near Kimberly, Oregon. The fossiliferous strata that have yielded beautifully preserved specimens of many of the animals we see domesticated today.

Dogs, cats, swine and horses are common. Oreodonts, camels, rhinoceros and rodents have also been found in this ancient deciduous forested area.

Here my talented young paleontologist cousin Spencer is holding a well preserved Oreodont skull.Many sites in Oregon yield beautifully preserved fossil shells laid down over 60 million years.
The asteroid that hit the Gulf of Mexico at the end of the Cretaceous caused a seafloor rift that split ancient Oregon. The massive hole left behind as the coastal lands slid northward filled in with sediment, refilling the basin.

These marine sediments were uplifted around the time of the birth of Oregon's Coastal Range. Easily collected and identified, as they look very similar to their modern cousins, you can dig for marine fossils all along Oregon's beachfront. I'll post some photos when I return from collecting later this year.