Cretaceous carnage #14
Carnosaur
MemberCompsognathusJanuary 16, 20152940 Views11 Replies- Einiosaurus procurvicornis v Ceratosaurus dentisulcatus
suggested this match on carnivora but it didn't attract a lot of attention..
Einiosaurus
Einiosaurus is a medium-sized herbivorous centrosaurine ceratopsian dinosaur from the Upper Cretaceous (Campanian stage) of northwestern Montana. The name means 'buffalo lizard', in a combination of Blackfeet Indian eini and Latinized Ancient Greek sauros; the specific name (procurvicornis) means 'with a forward-curving horn' in Latin. Einiosaurus was a herbivorous dinosaur. In 2010 Gregory S. Paul estimated its body length at 4.5 metres, its weight at 1.3 tonnes. Its snout is narrow and very pointed. It is typically portrayed with a low, strongly forward and downward curving nasal horn that resembles a bottle opener, though this may only occur in some adults. The supraorbital (over-the-eye) horns are low, short and triangular in top view if present at all, as opposed to the chasmosaurines, such as Triceratops, which have prominent supraorbital horns. A pair of large spikes, the third epiparietals, projects backwards from the relatively small frill. Smaller osteoderms adorn the frill edge. The first epiparietals are largely absent. Low-diversity and single-species bonebeds are thought to represent herds that may have died in catastrophic events, such as during a drought or flood. This is evidence that Einiosaurus, as well as other centrosaurine ceratopsians such as Pachyrhinosaurus and Centrosaurus, were herding animals similar in behavior to modern-day bison or wildebeest. In contrast, ceratopsine ceratopsids, such as Triceratops and Torosaurus, are typically found singly, implying that they may have been somewhat solitary in life, though fossilized footprints may provide evidence to the contrary. In 2010, a study by Julie Reizner of the individuals excavated at the Dino Ridge site concluded that Einiosaurus grew quickly until its third to fifth year of life after which growth slowed, probably at the onset of sexual maturity. Like all ceratopsids, Einiosaurus had a complex dental battery capable of processing even the toughest plants. Einiosaurus lived in an inland habitat.
Ceratosaurus
Ceratosaurus meaning "horned lizard", in reference to the horn on its nose (Greek κερας/κερατος, keras/keratos meaning "horn" and σαυρος/sauros meaning "lizard"), was a large predatory theropod dinosaur from the Late Jurassic Period (Kimmeridgian to Tithonian), found in the Morrison Formation of North America, in Tanzania and Portugal. It was characterized by large jaws with blade-like teeth, a large, blade-like horn on the snout and a pair of hornlets over the eyes. The forelimbs were powerfully built but very short. The bones of the sacrum were fused (synsacrum) and the pelvic bones were fused together and to this structure (Sereno 1997) (i.e. similar to modern birds). A row of small osteoderms was present down the middle of the back. Ceratosaurus was a fairly typical theropod, with a large head, short forelimbs, robust hind legs, and a long tail. Uniquely among theropods, Ceratosaurus possessed dermal armor, in the form of small osteoderms running down the middle of its back. The tail of Ceratosaurus comprised about half of the body's total length. It was thin and flexible, with high vertebral spines. The type specimen was an individual about 17.5 feet (5.3 m) long; it is not clear whether this animal was fully grown. David B. Norman (1985) estimated that the maximum length of Ceratosaurus was 20 feet (6 m). A particularly large Ceratosaurus specimen from the Cleveland-Lloyd Quarry (UUVP 81), discovered in the mid-1960s, may have been up to 28.8 feet (8.8 m) long. Marsh (1884) suggested that Ceratosaurus weighed about half as much as Allosaurus.
Nature doesn't deceive us; it is we who deceive ourselves.
@SR & Cryo - thanks guys! i appreciate your kind words :)
As far as i know, C. dentisulcatus is known only from the holotype(UMNH 5278)from the description paper..
"Diagnosis: In addition to significantly larger size, the
largest ceratosaur of record differs from Ceratosaurus nasicornis
in the following: subnarial border of premaxilla
arched and almost horizontal versus straight and dipping
forward; nasal process lower; body of premaxilla longer,
and with several large foramina; maxilla more massive,
alveolar border more concave, and recess more pronounced;
posterior edge of nasal process rises more steeply; front of
antorbital fenestra more open; three large openings into
body of maxilla at front of maxillary recess and base of
nasal process; 12 alveoli versus 15; teeth more massive and
more strongly recurved; dentary more massive and more
upturned from tooth 6 forward; dentary teeth more massive,
and only 11 versus 15; atlas-axis 100 mm long versus 84;
odontoid more prominent..."
Here's a skeletal done by hartman
as we can see, Dentisulcatus was a rather robust theropod for its size.
Hartman estimated its weight at ~1,500kg(3,300lbs or ~1.2 tons) so, it's approaching the size of its opponent.
Ceratosaurus(i believe the species used was nasicornis) jaws exhibit a great level of mechanical efficiency
Dentisulcatus, being larger, would (perhaps) exhibit even greater mechanical efficiency in its jaws; Ceratosaurus appears to be a "quick biter" based on these results. Even if C/. dentisulcatus is just an adult Nasicornis, these results are still impressive imo.
On top of this, the neck muscles of C. nasicornis are rather robust in nature, aiding in the biting efficiency
Fig. 8. A–C: Lateral flesh reconstruction of neck and jaw musculature
of Tyrannosaurus rex (A), Allosaurus fragilis (B), and Ceratosaurus
nasicornis (C). Tendinous attachments are rendered as white. Neck
muscle abbreviations are as in Figure 4. B: In Allosaurus fragilis, the
novel course of m. longissimus capitis superficialis is evident. d AlIn Ceratosaurus
m. longissimus capitis profundus and m. rectus capitis ventralis
are restored as robust, based on the large size of their insertions.
M. transversospinalis capitis has a relatively small insertion on the
parietals in Ceratosarus, and this muscle is restored here as slender
compared with that in Tyrannosaurus anlosaurus. Jaw muscle contractions
are: m. a.m.e. med. 5 m. adductor mandibulae externus
medialis. m. a.e.s., m. adductor mandibulae externus superficialis; m.
a.e. post., m. adductor mandibulae posterior; m. dep. mand., m. depressor
mandibulae; m. pt. ant., pterygoideus anterior/dorsalis; m. pt.
post., m. pterygoideus posterior/ventralis."
""Ceratosaurus: Slice and rake feeder. With its
large ziphodont teeth and inferred large muscles for ventroflexion,
Ceratosaurus may have raked its upper teeth
through prey similarly to large carnosaurs. With a large
inferred m. l.c.p., and especially a large m. r.c.v. acting on
a modest in lever, strikes or cutting action with the upper
teeth would have been high-geared, rapid actions. Large
origins of m. complexus indicate a large muscle cross-section
and high force production. Coupled with short
moment arms, high force indicates that m. complexus of
Ceratosaurus effected particularly rapid and powerful
head dorsiflexion and lateroflexion. Short moment arms
for most other muscles would have enabled rapid,
although not particularly forceful, movements of the
head.
Several osteological correlates of jaw muscles indicate
a more forceful bite in Ceratosaurus than would be
expected from the modest size of its adductor chamber."
http://api.viglink.com/api/click?format=go&jsonp=vglnk_14214630590569&drKey=1082&libId=e34e32ea-3dd1-438c-93d4-4eb09035deaf&loc=http%3A%2F%2Fcarnivoraforum.com%2Ftopic%2F10234122%2F1%2F%23new&v=1&out=http%3A%2F%2Fwww.ohio.edu%2Fpeople%2Fes180210%2FSnively%2520pdfs%2Fsnively_russell_theropod_necks.pdf&ref=http%3A%2F%2Fcarnivoraforum.com%2Fforum%2F3849751%2F&title=Einiosaurus%20procurvicornis%20v%20Ceratosaurus%20dentisulcatus&txt=http%3A%2F%2Fwww.ohio.edu%2Fpeople%2Fes180210%2FSnively%2520pdfs%2Fsnively_russell_theropod_necks.pdf
what all that scientific mumbo-jumbo means is that Ceratosaurus woul hae to be careful as to where it would bite, but it's bite would be very mechanically damaging.(i.e. cutting tendons, causing severe blood loss)
the biped would be more agile as well, which would allot it to possibly outflank the ceratopsian.
all in all, i like the odds for ceratosaurus here.
might actuaoly write this one out, just cuz though :D
Nature doesn't deceive us; it is we who deceive ourselves.
