Whole communities of ape-like creatures may have
been killed in volcanic disasters which struck East Africa 18 million
years ago, according to new research.
It follows a study of rock deposits close to the
once active volcano of Kisingiri. These contained fossils of what
is believed to be a forerunner of humans called Proconsul.
These creatures livid in a semi-arid environment
close to the mountain and the research suggests they may have been
caught by a pyroclastic flow. These are clouds of hot gas, dust and
rubble which travel at huge speeds from erupting volcanoes.
Scientists, who report their findings in the Journal
of the Geological Society, believe the abundance of the hominoid fossils
may represent "death assemblages" - whole populations wiped out
simultaneously by "glowing cloud" eruptions.
It is thought that many of the victims found in
Pompeii and Herculaneum who died in the AD 79 eruption of Vesuvius
were killed by pyroclastic flows.
The basis for the new revelation comes from Early
Miocene age rocks of the Rusinga Group, on the shores of Lake Victoria
in Kenya. The rock formation contains evidence of pyroclastic flows and
Research shows that in between eruptions, the landscape
became covered in mostly dry, deciduous, single-canopy woodland, with
some evergreen forest in restricted, low-lying areas.
Primates are thought to have evolved and thrived mainly
in forest habitats from the Eocene age, through part of the Miocene age.
During the Miocene age, conditions became more open,
culminating in the expansion of grasslands.
The fossils of the Rusinga Formation form a crucial
link between the early primates of the forest habitats, and human
forerunners of the more open-country habitat.
The new research on the fossils shows that these human
forerunners lived in drier conditions than had been supposed, on a
landscape that experienced repeated volcanic eruption.