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(including sauropods). Unlike the
Troodon
egg clutches, the clutches did not show
pairingoranypost-layingarrangementsbythesauropods,andlookedmorehaphaz-
ardly placed.
Paleontologists working the site were also excited to find six definite nest
structures directly associated with egg clutches. Five of these six nests were adja-
cent to one another and less than a meter (3.3 ft) underneath a bed with abundant
adult-sized sauropod tracks. All of this trace fossil evidence suggested that these
nests might have been made at about the same time, and that adult sauropods came
along later in the same place as the nests, perhaps to start another generation of ti-
tanosaurs.
Probably the most surprising trait of these titanosaur nests, though, was their
size, which did not match the proportions of their tracemakers. Instead, some of
these nests had about the same width and depth of the
Troodon
nests, measuring
about1to1.4m(3.3-4.6ft)wideand10to18cm(4-7in)deep,respectively;afew
were only half the size. Some of these nests—like those of
Troodon
—also had par-
tiallypreservedrims,althoughtheseweremadeofsandstone,notmicrite.Thenests
cut into an underlying well-stratified sandstone that was otherwise nearly identical
tothesandstonecomposingtherims,implyingthattherimswereoriginallyderived
from soft sand below. These were shockingly delicate works for creatures of their
size, like an elephant molding a peanut bowl out of clay.
However, where these nests diverged the most from the
Troodon
nests was in
their overall shape. Whereas the best-preserved
Troodon
nest was nearly circular
when viewed from above, the titanosaur nests were longer than they were wide,
giving them oblong or kidney-bean profiles. This made the titanosaur nests look
less like kiddie pools and more like troughs. Moreover,
Troodon
egg clutches were
tightly packed in a relatively small central area of the nest, whereas the titanosaur
eggs were spread throughout their nests, filling most of the interior space. Com-
plicating matters further, the expansion and contraction of soils around the eggs
