Geoscience Reference
In-Depth Information
ing dinosaur.These dinosaurs are everywhere around us,here and now,and making
traces.
We call them birds.
A Brief Introduction to Modern Dinosaurs, Their Evolution, and Their Traces
Nomatterwhereyouliveintheworld,itisnearlyimpossibletoavoidseeingnewly
made theropod traces. Given about 10,000 species of modern birds, then billions of
individual birds, multiplied by the thousands of traces a single bird can make in a
normal lifetime, it all adds up to a whole heap of traces. Go to the most inhospit-
ableplacesontheearth'ssurface,looklongenough,andyouarelikelytofindsome
sort of sign that a bird was there. Even urban environments are rich in bird traces,
especially those where birds such as pigeons (
Columba livia
) and American crows
(
Corvus brachyrhynchos
) have adapted and thrived. Bird traces thus add yet anoth-
er, deeper dimension to our appreciation of their makers.
Bird traces include their tracks, cough pellets, beak marks—probe marks in
sand, piercings in fruit, and drill holes in wood—as well as talon marks, nests, bur-
rows, gastroliths, droppings, food caches, dust baths, and broken seashells, to name
a few. Very broadly, most bird traces are related in some way to feeding and repro-
ducing,buttheseandotherbehaviorsaresoincrediblyvariedandnuanced,itiswell
worth taking a second look at their traces for whatever insights they might supply.
The ubiquitous presence of birds and their traces throughout the history of hu-
manity also led to their infusion into our lives as stories, idioms, and metaphors,
even featuring prominently in world religions. For example, a Cherokee story tells
how the Appalachian Mountains were made from the beating of a vulture's wings
against the earth; most Native American traditions also feature birds as important
parts of their spirituality. The Ngarrindjeri people of Australia have a Dreamtime
story about a rivalry between the emu (
Dromaius novaehollandiae
) and brush-tur-
key (
Alectura lathami
) that resulted in the emu becoming flightless and the brush-
turkey having smaller egg clutches in its nests.
