Geoscience Reference
In-Depth Information
novegetationalongtheway,thesauropodswouldhavehadaclearview,justincase
they needed advance warning of the big predatory theropods waiting for them out
there. Occasionally one or several of these theropods came down to the shoreline
too, hoping to pick off a straggling sauropod for a big score, but for the most part
they stayed away; this was sauropod country, and the uneven ground made ambush
huntingandquickpursuitsproblematic.Ifseenfromapterosaur'spointofview,the
coastal trails would have connected to more inland ones, criss-crossing the forested
interiors and freshwater wetlands like a great spider web.
Such grand disturbances of pliable mud or sand, in which great numbers of
overlapping footprints made by immense dinosaurs made trails or left churned
messes in the geologic record, are sometimes called “dinoturbation.” I personally
dislike this term, because it literally means “terrible [or awe-inspiring] mixing.”
Thishandiwork,however,isnottheexclusivedomainofdinosaurs.Afterall,earth-
worms and ants also mix tons of sediment every day. This term also distracts from
how a few modern vertebrates, such as elephants and hippopotamuses, are cap-
able of doing their own awesome mixing of sediment, which we somehow man-
age to restrain ourselves from labeling “elephanturbation” or “hippoturbation.” Se-
mantics aside, huge-sized dinosaurs, which sometimes traveled together in herds
like the proverbial ships passing in the night, would have left sedimentary wakes
with their passage, massively disturbing and altering terrestrial and freshwater eco-
systems wherever their feet landed.
As the largest living land animals, elephants are the first analogs ichnologists
reach for when trying to estimate the potentially far-reaching ecological effects
of dinosaur trails. Elephants consist of three species: the African bush elephant
(
Loxodonta africana
), African savannah elephant (
L. cyclotis
), and Indian elephant
(
Elephas maximus
). Of these, the African bush elephant (
L. africana
) is the largest,
with males weighing more than 7 tons, but Indian elephant males can also reach 5
tons. Elephants of all three species travel extensively and migrate annually. They
normally walk in groups led by an adult female (matriarch), although adult males
