The story of millions of years part 3
MIDDLE JURASSIC
Scotland…… 176 Million Years Ago
The large animal stepped with care, its massive hand sinking
deep into the sulphurous ooze, its foreleg coated to the wrist in brown slime
before lifting it again.
Immediately sediment rushed to fill the depression, the mud
and fine silt upon which the dinosaur walked being a viscous soup that deplored
a void.
As the hole filled so the dinosaur created another, its long
columnar legs ideally suited for stalking the primal mud.
Behind it, a trail wound up to higher ground; a scrubby headland
browsed back to earth, where it and others of its kind had ravaged all but the
tallest trees and toughest leaves.
Yet a fringe of horsetails mirrored the trail, marking the
boundaries of a stream, one of many that trickled down from the centre of the island;
the tough, silica-stalked plants a brilliant-green anomaly, being unmolested by
beak or teeth.
The dinosaurs wanted softer things to eat and to find those
they had to forage on the shore.
The tide was out, and having traversed the wide mudflats,
criss-crossed by the tracks of smaller feet, the large animal, a cetiosaur, had
set its tiny mind on reaching the shallows where lapping tides brought forth a
daily boon.
Here, at the margin of the lagoon, weed collected; a bladder-encrusted
tangle of nutrition. Other animals were already feasting, lifting their long
necks high into the air to swallow down the watery prize, and the cetiosaur
joined them, plundering the rank ribbon of rubbery vegetation.
There was food here for all, and not just the largest
dinosaurs, for between their immense shadows smaller creatures walked; nimble,
bipedal carnivores, ever cognisant of their gigantic companions yet wary only
of their feet.
These agile hunters picked and dipped, their arrow-pointed
snouts probing the dark gullies within the weed, searching out crabs and snails
and occasionally the silver sides of stranded fish, morsels they would hurriedly
gulp down.
And then, as they did all day every day, their foraging
would begin again, mudlarks and beachcombers working side by side.
As the day began to warm, the clouds stacking up in the sky,
so the cetiosaur, belly digesting, would amble towards the shallows; leaving
the sticky mud of the stagnant lagoon to wade towards the fertile sea.
Here, half submerged, the weight taken from its feet, it
could sit out the heat of the day, the salt and small fish cleansing its scaly
hide.
But today, that was not to be, three lithe hunters barring
its way; larger cousins of the small tridactyl diners with which it had shared
the beach.
These were megalosaurs, eustreptospondylids, and
collectively they posed a threat, three mottled hunters, reluctant, squabbling
companions, that nose to tail, arms slung low, prowled the sand bar; the thin
strip of land that divided the lagoon from the safety of the sea.
Alone they would step aside; the carnivores, not wise but
understanding on an instinctual level that there was easier meat to find, but
together, bolstered by numbers, they might take a chance and seize an
opportunity for all of them to feed.
The cetiosaur stood alert, neck high, its dim understanding
that of danger, torn between its habitual behaviour and the unfamiliar scene.
Soon, however, there would be no choice, as one by one other
megalosaurs arrived, large and small, emerging from the forest margins and
following their noses along the beach; their olfactory lobes pulsing with the
aroma of rotting meat.
A giant carcass lay washed up; dark on top, light beneath, a
four-flippered nightmare from the deep; shark-scarred and barnacled, the
largest killer of its age, cooking beneath the Jurassic sun after stranding on
the reef.