Very regularly, interesting artifacts of long gone animals
are being rediscovered across the globe-hiding in the fossil collections of our
museums. Back in 2009, scientists (specifically paleontologists) documented a “new”
animal hiding in storage at the ROM, Canada’s Royal Ontario Museum.
The 500-million-year-old hurdia
victoria, a sea creature, was initially recovered from Yoho National Park,
near Field, B.C. by American paleontologist Charles Walcott in 1909. Included in the find was a mysterious carapace
(upper part of the exoskeleton) which Walcott recognized as that of a crustacean. The fossils were eventually packed up and
shipped to the ROM, where they floundered for quite some time.
Some parts of the remains were misidentified. The mouth section was thought to be a whole
jellyfish. Another piece was initially
identified as a sea cucumber. Walcott
tried to identify the fossils by comparing them to known species, especially
living ones. By the time Walcott was 74,
he had recovered over 65,000 specimens from the Burgess Shale, a vast fossil
field in the Rocky Mountains of BC. The
shale holds fossils of things that lived about 500,000,000 year ago in the Middle
Cambrian period and are excellent specimens.
The Burgess Shale once lay beneath the sea deeply enough so as to not be
disturbed by waves of storms, buried beneath mud flows off the Cathedral
Escarpment. This enabled preservation of
soft tissue because the mud insulated the remains from decay.
Walcott’s misidentification remained intact until the 1960’s. Alberto Simonetta, an Italian paleontologist,
reinvestigated the Burgess Shale and was able to convince the scientific
community that there were many more artifacts, and that Walcott’s
identifications were incorrect. Harry
Blackmore Whittington, with the help of research students Derek Briggs and
Simon Conway Morris of the University of Cambridge, reassessed the deposits and
revealed that the fauna represented were much more diverse than Walcott had
recognized. Many of the animals present
had bizarre anatomical features. Some of
the new animals were the Opabinia, with five eyes and a snout like a vacuum
cleaner hose and the Hallucigenia, which walked on bilateral spines.
In the 1980s, the ROM discovered more complete examples of
the hurdia victoria body. In 2009, a hundred years after the first discovery, a
Canadian PhD student named Allison Daley put together the various pieces and
finally revealed the actual shape. Dr. Daley is currently a post-doctorate
researcher at the Palaeontology Department of the British Natural History
Museum.
Hurdia was one of the largest organisms in the Cambrian
oceans, reaching approximately 50 cm in length. It had a pair of spiny claws on
its head and a mouth like a pineapple ring. A hollow, spike-shaped shell
protruded from the front of its head but the function of this organ is unknown.
The shell is empty and does not cover or protect the rest of the body. Large
gills were suspended from the sides of the body on lateral lobes. This animal was an important link in the
evolution of arthropods (animals with jointed legs- crustaceans, butterflies, spiders
and other insects) and their diet of beings that would evolve into
mammals.
UNESCO (The United Nations Educational, Scientific and
Cultural Organization) and Parks Canada designated the Burgess Shale as
culturally and scientifically important.
This made it more difficult for scientists to quarry the fossils, but The
Burgess Shale Geoscience Foundation and the ROM do have ongoing sites. Even now samples come in faster than they can
be identified and catalogued.
The story of the hurdia victoria underscores the vast amount
of information we have yet to understand.
Buried deep within not only fossil beds, but also museum storage, may be
many answers to cataloguing and identifying some of the mysterious animals
reported in modern times.
Further reading:
Great article, but one correction needed. The Burgess Shale fauna of the Cambrian lived around 500,000,000 years ago, not 500,000 years ago.
ReplyDeleteOops--sorry! Corrected and many thanks!
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