The Burgess Shale - Fossil Ecosystems of North America: A Guide to the Sites and their Extraordinary Biotas - page 33

By 1912 Walcott had published many of
his finds and, of the 170 species currently
recognized from the Burgess Shale, over
100 were described by Walcott himself.
Walcott's Burgess Shale Quarry ( 29,
30 ) lies at 2,300 m (7,500 ft), just below
the top of Fossil Ridge, which connects
Mount Wapta and Mount Field. It is a
stunning location. Looking west from the
quarry, which remains snow-filled even in
the summer, a breath-taking panorama of
snow-capped mountains, glaciers, lakes,
and forests is revealed. Mount Burgess
points skywards, the vivid green Emerald
Lake is to its right, with the Emerald
Glacier poised above it. The site of
Walcott's camp can be made out on the
High Line Trail below.
Walcott also collected higher up the
mountain at a site now called the Raymond
Quarry after its detailed excavation in the
1930s by Professor Percy E Raymond of
Harvard University, whose collection now
resides at the Museum of Comparative
Zoology at Harvard. Apart from the work of
Alberto Simonetta, an Italian biologist, who
made detailed descriptions of some of the
Burgess trilobites in the 1960s, little further
work on these remarkable fossils was
carried out until the notion of a complete
restudy of the Burgess fauna was proposed
by Professor Harry Whittington in 1966.
Whittington is an Englishman, but
in 1966 was Professor of Paleontology at
Harvard University. He managed to
persuade the Geological Survey of
Canada that a restudy was timely and
collecting trips in 1966 and 1967
produced over 10,000 new specimens,
although few new taxa. In 1966
Whittington moved from Cambridge,
Massachusetts, to Cambridge, England,
and took the project with him. Very soon
he recruited two young postgraduates to
assist in the huge task of redescribing the
Burgess animals, Derek Briggs, taking on
the arthropods, and Simon Conway
Morris, the worms.
The Cambridge team made painstaking
dissections, drawings, and detailed photo-
graphs of the Burgess fossils and revealed a

wealth of new data unseen by previous
workers. Whittington produced a detailed
restudy of Walcott's first find, the 'lace crab',
Marrella , the most common animal from the
Burgess fauna, and set new standards for the
description of Burgess fossils. Briggs and
Conway Morris worked respectively on two
of the real enigmas of the Burgess
Problematica, Anomalocaris and Canadia
sparsa (later renamed Hallucigenia ) and by
remarkable detective work were able to
elucidate the true affinities of these most
bizarre Burgess animals.
In 1975 Desmond Collins of the Royal
Ontario Museum (ROM) in Toronto
obtained permission from the Park
Rangers to collect loose material from the
ridge. This party returned in 1981 and
1982, this time to look for new localities,
and demonstrated that the fossiliferous
beds were actually more extensive than
had been thought, with 10 or more new
locations, both above and below Walcott's
quarry, all along the line of the Cathedral
Escarpment.
In 1981 the site was designated a World
Heritage Site by UNESCO. The work of the
ROM team continued throughout the 1980s
and 1990s with some remarkable finds.

S TRATIGRAPHIC SETTING
AND TAPHONOMY OF THE
B URGESS S HALE
The Burgess Shale Formation is about
270 m (886 ft) thick and includes
10 members (Fletcher and Collins, 1998),
one of which, the Walcott Quarry Shale
Member, includes the productive layers in
Walcott's quarry which have yielded the
well-preserved, soft-bodied fossils. This
thick formation is the deep-water lateral
equivalent of the much thinner platform
facies of the Stephen Formation ( 31 ) and
is Middle Cambrian in age, approximately
510 million years old.
Just to the north of Walcott's quarry
the dark shales of the Burgess Shale
Formation abruptly disappear and abut
against much lighter-coloured dolomites
belonging to the Cathedral Formation
with an almost vertical contact ( 31 ).