The jebels scattered along
the coastal plain of Abu Dhabi's Western Region are the only vertebrate-bearing
Late Miocene rocks known from Arabia (Whybrow
and Hill, 1999). The majority of the fossils collected by the Natural
History Museum/Yale University team come from Baynunah Formation outcrops
(Whybrow et al, 1999; Whybrow,
1989; Whybrow et al., 1990) located
between the road from As Sila to Abu Dhabi and the coast. Here, fluvial
clastics deposited by a major river system (Friend,
1999) contain remains of invertebrates, reptiles, birds and mammals
as well as poorly fossilised plant material. Few vertebrate fossils have
been found at localities to south of the main road. The jebels in this
area lack the gravels and coarse sandstone lithologies seen in the lower
part of the Baynunah Formation at the coastal exposures; sediments forming
these southern jebels might be higher in the Miocene sequence (the "upper"
part of the Baynunah in Friend, 1999).
The most eastern fossiliferous locality is south of Tarif. Here a magnificent
partial skull of Tragoportax cyrenaicus (Gentry,
1999b) was the only fossil found in homogeneous red coloured sandstone
(a road cut exposure) by staff of the United States Geological Survey
(Hill et al., 1999).
Excepting the sea cliff outcrops
of the Baynunah Formation, "clean" exposures of Miocene sediments
are rare. The region is hyper-arid and during the 15 years or so of work
by the Natural History Museum/Yale University team, torrential rain has
occurred just five times. Detritus, a mixture of weathered Miocene sediments
with modern wind-blown sand, on the slopes of most jebels can be 20 cm
deep before un-weathered rock is reached. It is likely that material collected
early during the project, 1989-1992, had been exposed for several decades.
Although the Baynunah Formation
crops out in an area of about 1,8002 km, the 900+ fossils identified so
far come from a 5,602 km area. Except for the disarticulated, scattered
bones of a proboscidean found at Shuwaihat (Andrews,
1999; Tassy, 1999), almost all
vertebrate fossils are found as isolated elements, often fragmented by
extremes of temperature and rehydration of microcrystalline gypsum during
precipitation of winter fog and dew.
During the period that the
Natural History Museum/Yale University team, and others, have been finding
fossils from the Baynunah Formation, we have collected all material from
each locality that might be identifiable so that a possible collecting
bias is minimised (Hill, 1987). However,
some bias has been unavoidable because further collecting at some localities
has not been possible, especially from 1992. The development of the Western
Region, Emirate of Abu Dhabi, proceeds rapidly. Access to some localities
that were relatively easy to visit in the early 1980's is now prohibited.
We have suggested to the Emirate of Abu Dhabi authorities that some localities
should be conserved for the scientific heritage of the Emirate as well
as for international science. This suggestion was, in 1995, well received
and it is likely that Shuwaihat will be recognised as a locality of scientific
heritage. No progress has been made since that time and in 2001 it was
noticable that there was an increase in "holiday homes" and
associated rubbish on Shuwaihat.
Here we list (see Contents) and describe the localities and sites (within these localities), from west to east and their fauna and flora. The geographical coordinates listed for the sites were obtained using the GPS system. Although the error is said to be in the region of 25 metres (most sites cover a greater area than this) and that the GPS was subject to degradation by the United States Department of Defense, good coordinates for the main sites (Jebel Barakah, Shuwaihat, Jebel Dhanna) were obtained during January 1991 at the time of the Gulf War.
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