Name: Byronosaurus
(Byron lizard).
Phonetic: By-ron-o-sore-us.
Named By: Norell, Mackovicky and Clark -
2000.
Classification: Chordata, Reptilia, Dinosauria,
Saurischia, Theropoda, Tetanurae, Coelurosauria, Troodontidae.
Species: B. jaffei (type).
Type: Carnivore.
Size: 1.5 meters long.
Known locations: Mongolia, Ukhaa Tolgod.
Time period: Campanian stage in the late Cretaceous.
Fossil representation: Remains of two adults and two
juveniles.
One
of the
troodonts,
Byronosaurus aquired its name after
being named after
Byron Jaffe, a supporter of the American Museum of Natural History
Paleontological Expeditions.
One
of the unearthed skulls
of B. jaffei is the best persevered skull
specimen of any troodont,
and shows two adaptions that are unique among the currently known
troodonts. The teeth of Bryonosaurus are needle
like and without
serration, unlike the serrated teeth of its other troodontid
brethren. This adaptation suggests that Byronosaurus
may have focused
upon smaller prey animals like lizards and invertebrates. The
second important feature
is that the nasal passage connects with the antorbital fenestra
suggesting a highly developed sense of smell. Such an adaptation
would have proven very useful in hunting small prey items hidden from
view.
Another
interesting fossil
discovery relating to Byronosaurus is two juvenile
skulls found in the
nest of the oviraptorosaurid Citipati.
There are two predatory
theories for
their presence there, either the citipati parents
raided a
Byronosaurus nest to feed their young, or the Byronosaurus
juveniles
were the ones doing the raiding. A third possibility is that
Byronosaurus were nest parasites, as eggshell that
was found attached
to the juveniles is like the other oviraptosaur eggs. A modern day
version would be a cuckoo laying one of its own eggs in the nest of
different bird species. Of course this is not absolute proof that
nest parasitism occurred in Byronosaurus, but it
raises an
interesting possibility of how past creatures interacted with one
another beyond just predator and prey.
Further reading
- A new troodontid theropod from Ukhaa Tolgod, Mongolia. - Journal of
Vertebrate Paleontology 20(1):7-11. - M. A. Norell, P. J. Makovicky
& J. M. Clark - 2000.
- Osteology and relationships of Byronosaurus jaffei
(Theropoda:
Troodontidae). - American Museum Novitates 3402: 1–32. - O. J.
Makovicky, M. A. Norell, J. M. Clark & T. E. Rowe - 2003.
- Estimates of body size and geological time of origin for 612 dinosaur
genera (Saurischia, Ornithischia). - Florida Scientist 69 (4): 243–257.
- R. Montague - 2006.
- The perinate skull of Byronosaurus (Troodontidae)
with observations
on the cranial ontogeny of paravian theropods. - American Museum
Novitates, 3657: 51 pp. - G. S. Bever & M. A. Norell - 2009.