Geoscience Reference
In-Depth Information
das by directing animals to carry out their wishes. This tyranny started with seed
plants,whichdevelopedintheDevonianPeriod(about400million yearsago),then
escalatedintooutrightslaverywiththeevolutionoffloweringplantsintheLateJur-
assicPeriod,about145to150millionyearsago.Floweringplantswereparticularly
crafty, developing soft, delicious, juicy, sugary fruit that surrounded seeds. It was
evolutionary bribery at its best: I give you food, you bear my children, and oh, by
the way, give them a ride while you're at it. You see, while the fruits are digestible,
the seeds are not. Hence, these pass through animal digestive tracts unscathed and
come out the other end, covered in warm fertilizer.
What flowering plants started, then, was a combination of seed dispersal and
seed planting, which non-avian and avian dinosaurs likely helped throughout the
end of the Mesozoic. Today, birds and mammals have shaped entire landscapes by
eating fruit, carrying seeds in their guts, and pooping. This is a topic we will revisit
toward theendofthis topic asweconsider howdinosaur traces molded ourmodern
world and will continue to affect it.
Last Suppers and Permanent Constipation: Dinosaur Stomach and Intestine Con-
tents as Trace Fossils
If put in the same order as an alimentary canal, trace fossils related to dinosaur
feeding typically start with toothmarks and end in coprolites. So what trace fossils
are between these two end members? Gastroliths certainly qualify, and as discussed
before, enough of these are preserved in dinosaur abdominal cavities to inform us
about dinosaur behavior. But what about the digested food itself? Does any of this
getpreserved?Yes,indeed.Preservedcontentsofstomachs,intestines,andanything
else that resided in a dinosaur's gut—but did not make it out in one form or another
before that dinosaur died—are also trace fossils. What about dinosaur hurling? In
ichnology, this counts too; it just needs to have been preserved in the fossil record,
and then ichnologists would very happily label these as trace fossils.
Before going on any further, a little more jargon is needed to know how pa-
leontologists name such trace fossils. Most broadly, any former food item asso-
