Canadian Scientists Provide Insight into Bizarre New Filter Feeding Animal 

The Burgess Shale (British Columbia, Canada) is regarded as one of the world’s most important fossil locations.  This UNESCO World Heritage site, discovered over one hundred years ago has yielded thousands of Middle Cambrian marine fossils.  The beautifully preserved specimens have provided scientists with a fascinating glimpse into an marine ecosystem that existed approximately 505 million years ago.

The Burgess Shale

Although, these highly fossiliferous shales have been known about since 1909, they are still capable of providing surprises and this week, a team of Canadian researchers have published a paper on a strange, filter feeding animal, that resembled a tulip.

The strata which contains the remains of these “Tulip beds” was first explored more than twenty-five years ago and more than 1,000 actual fossil specimens are known but these strange creatures, a bizarre type of invertebrate that is difficult to place in taxonomic phyla has just been formally named and described.  The newest member of the Burgess Shale ecosystem is to be known as Siphusauctum gregarium.  The formal scientific name describes the filtering feeding mechanism with which this animal obtained nutrients as well as recognising the gregarious nature of this bizarre Cambrian beastie.

Siphusauctum gregarium

The name means (gregarious, large cup).  Although, not living in a colonial structure such as a sponge colony or a coral, these animals did congregate together, perhaps exploiting a particularly rich feeding area.  One slab of shale contains the remains of at least sixty-five individual animals.  It seems that the group (or should we refer to them as a “field”) was wiped out when that area of the seabed suffered some catastrophic event and was covered in a sudden deposit of sediment.

The fossils indicate that these creatures reached lengths in excess of 20 centimetres and a paper analysing these has been published online in the scientific journal “The Public Library of Science”.

Strange Filter Feeder of the Middle Cambrian – S. gregarium

Bizarre filter feeder of the Middle Cambrian.

Picture credit: M. Collins/Royal Ontario Museum/University of Toronto/PLoS One

The organism seems to be adapted to a benthic existence (living on the sea floor).  There is a single hold-fast structure which would have been partially submerged in the mud helping the organism to remain in one place.  A long stem, with an an internal tube, surrounded by a sheath supports the feeding mechanism and the gut above the sea floor.  This new type of stalked filter feeder had its gut, anus, other organs including a simple, straight digestive tract housed in an egg-shaped structure that was perched on top of the stalk.

This bulbous structure (known as a calyx)  resembles the head of a tulip flower.  A flexible sheath covers the calyx, there are six small, circular openings at the base of this structure and a central orifice at the top (believed to be the anus), surrounded by other smaller openings.  The creature seems to have a six-fold radial symmetry with each of its six segments having cilia (fine hair-like appendages), surrounding a body cavity that contained the stomach and other organs.

The Scientific Paper

The paper’s lead author Lorna O’Brien, a PhD student at the University of Toronto, postulates that S. gregarium was a filter feeder, with water passing through the openings and the fine hair-like appendages could “comb out” food particles.  These creatures probably were able to actively pump water through themselves rather than passively waiting for food to drift through their various openings.  Like many other strange creatures from the Burgess Shale, scientists are unsure what animals alive to day are the descendants of these creatures, or whether S. gregarium represents an evolution of a life-form that simply left no modern descendants – a sort of evolutionary experiment that failed to work.

Student Lorna stated:

“Most interesting is that this feeding system appears to be unique among animals.  Recent advances have linked many bizarre Burgess Shale animals as primitive members of many animal groups that are found today but Siphusauctum defies this trend.  We do not know where it fits in relation to other organisms.”

How these strange creatures relate to modern phyla remains unclear, Lorna and her PhD supervisor, Jean-Bernard Caron (Curator of Invertebrate Palaeontology at the Royal Ontario Museum (Toronto), suggest that another bizarre fossilised creature Dinomischus – a stalked Cambrian filter feeder may have a similar role in the ecosystem, but S. gregarium seems to have lived at much greater depths and formed an much larger proportion of the fauna. Dinomischus spp  seem to be solitary, but S. gregarium formed large beds.

Nearly all the specimens known are compressed and fragmented, just one specimen has been found so far that was compressed vertically to reveal the six-fold radial symmetry.  It is likely that these animals were soft-bodied, but their relationship to earlier fauna, such as the Ediacaran fauna also is unclear.

Some of the Best Preserved Fossils of Siphusauctum gregarium

Tip-toe through the “tulips”.

Picture credit: Royal Ontario Museum/University of Toronto/PLoS One

The Burgess Shale (and the Chengjiang – another important Cambrian fossil site, in Yunnan, China), provide an amazing insight into the diversity of life in the oceans around 500 million years ago.  Who knows what other bizarre fossils lie awaiting discovery and study in these extensive fossil beds.

To view replicas and models of iconic Palaeozoic animals: CollectA Prehistoric Life Models.

Fierce Brazilian Predator that Roamed Long Before the Dinosaurs

Long before the dinosaurs evolved, terrestrial habitats were dominated by different kinds of reptiles, some of which were fearsome hunters, larger than most of the land carnivores found today.  A team of South American scientists have published a paper on one such formidable creature – an animal with huge canine teeth like a modern day tiger, but weighing twice as much as the biggest “big cats” around.

Ancient Permian Predator

Named Pampaphoneus biccai this new genus of ancient reptile is believed to be the earliest, large predator discovered to date in South America.  The name means “Bicca’s Pampas Killer”, honouring the land owner (José Bicca), as the fossils were found on his farm.  Described as a Dinocephalian therapsid, a group of Late Permian to Triassic reptile-like synapsids that include the ancestors of mammals, this animal was probably the top predator in the region in the Late Permian.

Pampaphoneus biccai – Vicious Permian Predator

The “Pampas Killer” on the hunt.

Picture credit: Voltaire Neto/Wits

Known from just a single skull, the fossils were first unearthed back in 2008, but the scientific paper which has been published in the scientific journal Proceedings of the National Academy of Sciences, was delayed as it took many hundreds of hours to carefully piece the skull together from the many fragments that had been found at the fossil site.

Pampaphoneus biccai

The discovery will help scientists to understand how this type of therapsid reptile diversified towards the end of the Permian period – Guadalupian/Lopingian epochs (265-260 million years ago), as they gradually replaced the pelycosaurs (animals such as the sail-backed reptile Dimetrodon), as the dominant large vertebrates on land.

To discover exposed sediments on the extensive grasslands of Brazil, the scientists employed images from Google Earth to assist them in their search.  Satellite images helped the team identify potential fossil sites which were not covered by vegetation, thus permitting the rock layers to be explored more easily.  This is not the first time that satellite technology has been employed to search for fossils in this way, many dinosaur fossils have been found using this technique.

With much of the Earth’s surface comprehensively mapped, scientists are able to pin point with great accuracy potential fossil yielding dig sites.  In the past, such locations were often discovered by painstakingly walking over an area or relying on reports of unusual finds from locals.

The restored skull measures over 35 centimetres in length.  It indicates that with its over-sized canines and other saw-like teeth this predator had a powerful bite.

Using more complete fossil specimens found in the Karoo Basin region of South Africa, the Brazilian palaeontologists have been able to build up a picture of what this four-footed predator looked like.   They estimate that it would have been over 3 metres in length, weighing in excess of 300 kilograms.  This makes it larger and heavier than the largest species of “big cat” predator found today.  Consider the prospect of a Komodo Dragon with the power and strength of a Siberian Tiger, and you are beginning to get an impression of what “Pampas Killer” would have been like.

The Restored Skull of Pampaphoneus biccai

Fierce Permian predator.

Picture credit: Dr Juan Cisneros

The Brazilian scientists worked with other palaeontologists and experts from Turkey and South Africa as they studied the skull bones and began to piece them together.  South Africa, the region known as the Karoo Basin, is a particularly rich source of Late Permian reptile fossils.  During the Late Permian, most of the land masses were squeezed together to form a single super-sized continent known as Pangea.

The southernmost portion of Pangea consisted of South America, Africa, India, Antarctica and Australia.  Studies of fossil plants found in these regions indicate that Pampaphoneus biccai lived in a relatively cool, forested climate.  This suggests that during the Late Permian, Brazil was actually much closer to the South Pole than it is today.

For models and replicas of prehistoric creatures from the Permian: CollectA Prehistoric Life (Deluxe Models).

Scientists hope to use the fossil evidence from South America to help build up a picture of therapsid diversification and migration during the Late Permian.  P. biccai may have been a very formidable predator, but this type of reptile was doomed to extinction just a few million years later.  Changing sea levels, an asteroid/comet impact and extensive flood basalt eruptions in what was to become Siberia led to perhaps the most devastating mass extinction event identified to date in the fossil record.

Ninety-five percent of all types of life on Earth became extinct at the end of the Permian.  The therapsid group of reptiles were severely affected.  Some twenty-one families of therapsids (63 percent) died out.