Geoscience Reference
In-Depth Information
We can be relatively sure that mother or father sauropods did not sit on their
egg clutches afterwards, or if they did, they did not pass on those genes. (See previ-
ous caveats about dropping eggs from great heights.)
Knowing about the nesting behavior of these titanosaurs and
Troodon
also
makes one wonder if they stayed in the same place after laying their eggs, however
temporarily that might have been. In other words, did they have any post-hatching
care, like that seen in modern crocodilians and birds, or other dinosaurs like
Mai-
asaura
? We don't know an answer for sure yet, although some sauropod tracksites
show a wide range of sizes in their tracks—from very small to extra
large—suggesting that young sauropods and parents may have been in the same
place and time. A few instances of adult sauropod skeletons preserved with much
smaller, juvenile ones, such as in a few instances with
Camarasaurus
, also argue
for young sauropods sticking close to their parents for a while after hatching. One
thing is for sure: This question could be better answered by studying a combination
of trace fossils, such as nests and tracks together.
The Oldest Dinosaur Day Care
Dinosaur body fossils make up the bulk of evidence for documenting the earliest
years of dinosaurs, consisting of eggs, embryos, hatchlings, and half-grown juven-
iles. Although this wealth of information provided by unborn and baby dinosaurs
has contributed to our understanding of dinosaur life cycles, paleontologists still
havetofacetherealitythattheseallrepresentlivesthatweresnuffedoutbeforethey
behaved much. As just discussed, what do we know about the lives of hatchlings
freeing themselves from their enclosing eggshells? How would we know through
trace fossils whether newborn dinosaurs were altricial (depending on their parents
for extended care), or precocial (able to leave mom and dad soon after hatching)?
Furthermore, what clues can trace fossils give us about when such behaviors first
evolved in dinosaurs?
One of the most impressive dinosaur nest sites with other trace fossils to ad-
dress these questions is in Early Jurassic rocks of South Africa from about 190
