Shortfin Mako Shark vs. Koolasuchus cleelandi

[dinosauria101]

Shortfin Mako Shark -Isurus oxyrhinchus

upload.wikimedia.org/wikipedia/commons/thumb/2/2f/Isurus_oxyrinchus_by_mark_conlin2.JPG/1024px-Isurus_oxyrinchus_by_mark_conlin2.JPG

Order: Lamniformes
Family: Lamnidae
Length: 3-3.5 meters
Mass: 60-550 kg, possibly up to 1 tonne
Diet: Marine animals
Weapons: Slicing jaws
One of the most fast, agile, and athletic of all shark species. Has been known to eviscerate prey with fast bites

Koolasuchus cleelandi

i.ytimg.com/vi/izMJ-5cMAtg/maxresdefault.jpg

Order: Temnospondyli
Family: Chugutisauridae
Length: 4-5 meters
Mass: 500 kg
Diet: Fish
Age and Location: 110 million years ago, Early Cretaceous, Australia
Weapons: Slicing jaws
The last temnospondyl amphibian. Thought to have survived because it lived in an area too cold for competitors

[Infinity Blade]

I've been wondering about this for a while: does anyone have any published description of Koolasuchus' teeth? I've seen them pictured once, but they looked somewhat worn by taphonomy (only look at A-C; D-G are the teeth of plesiosaurs). The way I intuitively imagine them, they'd be (numerous) small, conical teeth meant for gripping.

Edit: I found the description paper->.

The dentition consists of a dentary tooth row of approximately 40 marginal teeth and a symphyseal tusk, with no postsymphyseal tooth row and no teeth on any of the coronoids. All teeth in which the tips are preserved are curved inwards with lance-shaped tips bearing mesial and distal keels, a structure similar to that found in the teeth of Siderops kehli (WARREN & HUTCHINSON 1983), although in K. cleelandi these keels are not serrated as they are in S. kehli. A tooth broken near its base shows the extremely convoluted, labyrinthine pattern to be expected in a tooth of this diameter: approximately 15 mm, measured at the base (WARREN & DAVEY 1992).

Although Jupp & WARREN (1986) earlier suggested that NMV P156988 could be a member of the Plagiosauridae, largely because of its extreme dorso-ventral flattening, that assignation is now discounted because the flattening of two of the mandibles has been shown above to be due to post mortem distortion. In addition, plagiosaurs lack a symphyseal tusk (with one possible exception, MICHAEL SHISHKIN, pers. corn. 1991), and commonly have teeth on all three coronoid bones, whereas K. cleelandi has a symphyseal tusk and lacks coronoid teeth.

So what we can gather is that this thing had inward-curved, pointed teeth with lanceolate tips. These teeth had carinae, albeit not serrated ones. Additionally, these teeth could get fairly large, especially towards the anterior end of the mandible, with the largest mandibular teeth being these tusks on the symphysis.

Skull midline length is estimated to have been 65 cm.

Available evidence suggests that while the Brachyopidae survived in the Northern Hemisphere, in Gondwana the brachyopids were outlived by the Chigutisauridae, the only possible exception being the brachyopoid from South Africa. Also of interest are the disparate sizes of members of the two surviving families, those from Laurasia being relatively smaller (estimated skull midline lengths: Gobiops, 90 mm; Sinobrachyops, 120 mm) than their Gondwanan counterparts (Siderops, 600 mm; Koolasuchus, 650 mm).

The skull and jaws, of course, are extremely broad.



I'm impressed. Sounds like this thing was indeed quite well armed.

[dinosauria101]

Good post! That's actually pretty impressive for an amphibian, I must say.

[6f5e4d]

The shark will win, it's heavier and with better adaptations to the water than Koolasuchus.

[dinosauria101]

I'd give this to the mako shark too. More agile and athletic, does not need to breathe, and more durable due to tougher hide. It may be able to eviscerate the Koolasuchus if it can attack underneath

[jhg]

The shark takes it I guess?

[Infinity Blade]

Honestly, this is a pretty absurd matchup, if Koolasuchus' skin is anything like that of the vast majority of modern lissamphibians. While it is true that many temnospondyls had scales, which might theoretically prevent dehydration in salt water, Mesozoic stereospondyls (like Koolasuchus) had thinner scales than their Paleozoic predecessors, presumably for increased cutaneous respiration. Some lineages even lost them completely (Witzmann, 2007)->. Koolasuchus will likely not fare well in salty ocean waters (even if it had scales, those will likely not allow it to survive indefinitely in salt water), and to my knowledge makos don't venture into fresh water.

[creature386]

The mako takes this in anything but the shallowest of waters. Honestly, the Koolasuchus' only advantage I can think of is that its short limbs aren't as much of a target as the mako's broad pectoral fins. The shark's better maneuverability, tougher hide (this match is almost the inverse of GWS vs saltie in that regard) and probably better bite are just too much for the temnospondyl.

[Ceratodromeus]

Mako even in shallow water.

[DonaldCengXiongAzuma]

The mako shark will win. It has a better bite, is more agile, and has more stamina.