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Re: [Re: [Part 2: Terramegathermy (very long, too)]]
> > Not much. Mainly the argument from generational turnover: *Deinosuchus*
> > needed 50 years to reach 10 m. If a sauropod would already have been 100
> > years old when reaching _adult size_ (recent articles say 10 years based
> > histology), the populations would have been endangered all the time, and
> > fossil record would look different (contain far, far less adult
> > and more younger ones).
> Personally I have my doubts about the _Deinosuchus_ study (i.e. are
> reliable indicators of bone growth? Why not long bones or vertebrae?)
No idea... maybe none are known...
> As for the sauropod pop, would we find more young? Adults have more time
> friendly bones, young bones break easy and would have less of a chance of
I guess we would find more subadults and even less adults. This may,
depending on taphonomy, not even be falsifiable... :-(
> I mean how many young _Deinosuchus_ fossils do we have?
> > P&L suggest why -- because the populations of adult animals of sauropod
> > size are very small, they must have crashed from time to time, leaving
> > young alone. This is a problem for mammals and many birds, which depend
> > heavily on their parents.
> So then, they are not advocating sauropod parenting?
Not much. They think megadinosaurs were more r-strategists than megamammals.
This may offer a reason (if any is needed) why theropods often approached
but apparently never exceeded 15 m and why no flightless birds have come
close to even 1 ton (though no birds probably had the time to evolve
this...). Juvenile tyrannosaurids don't look cute (long snouts...), which
has been regarded as evidence they were quite independent from their
> > > Sauropods [...] never dealt with temperatures as extreme as
> > > those the leatherback faces.
> > The other way round, as HP Randy Irmis has pointed out.
> Okay so then *most* sauropods didn't deal with this type of cold
No... unless polar sauropods evolved a different metabolism from others
> > > Auffenberg is his 81 study of _V.komodoensis_ states that "adults may
> > > move as much as 10km/day..." Now, barring the fact that this is yet
> > > another island species I'm using, that is still a pretty hefty
> > This is becoming more interesting, but it is still much less than 2 -- 5
> > km/h...
> I'm not sure I followed your statement here. Care to elaborate?
I was assuming that the monitors walk constantly for several hours (10 hours
gives 1 km/h, 5 hours gives 2 km/h...). May be naive... :-]
> > For how long can a Komodo monitor walk? An hour? :-/
> Unsure; oras probably don't make very good test subjects for treadmill
> so I wouldn't be surprised if no such endurance study was done on them.
> Auffenberg does mention chasing an ora on a motorcycle for .5 km. But, the
> animals was doing 14 km/hr at the time.
> As for the carnivores, Auffenberg himself, mentions that
> ambush predators seem to grow to very large sizes. This could explain the
> large theropods [...]
I disagree. Tyrannosauroids at least are built a lot like runners, and quite
different from *Pristichampsus rollinatii*.
> > > Great, now as long as the prey item doesn't make any sharp turns
> > > _T.rex_ will be set ;)
> > I don't understand this...
> Just making a jab at the pursuit hunting _T.rex_ hypothesis. Biomechanical
> studies on large theropods seem to indicate that they couldn't make sharp
> turns. This would be a problem for a pursuit hunter if the prey keeps
> and zagging. Now if one was an ambush hunter...
I don't think anything the size of *Edmontosaurus* or *Triceratops* can zig
& zag, at least not faster than *Tyrannosaurus*...
> > > Much of which I can certainly agree with; I just don't see why you
> > > need to shove them into the inefficient realm of tachymetabolism to
> > > achieve this.
> > Hm. Considering that tachymetabolism has not been selected against in
> > birds, mammals, and others, it must have some advantage...
By this I meant, if early birds were bradymetabolic, why didn't recent birds
keep that efficient adaptation?
> That tachymetabolism is only found in birds and mammals
> seems telling to me
> Perhaps once one goes forward they cannot go back.
> Does anyone know if naked mole rats have truly dumped their L.C.
I don't know, but I don't think so. AFAIK they just have burrows instead of
> > 2. From TV observations (not field observations, though...) I claim
> > predator/prey ration is much higher than that of tigers. There are just
> > of them.
> From: Behavioral Ecology of the Komodo Monitor.
> Though there is great disparity in comparing the values for oras and the
> mammalian predators, when the latter are considered in terms of the
> porportionate difference in predator size and waste percentage of prey,
> disparity is not nearly as great. Thus, though the size ratio of an adult
> to an adult tiger is 1:3, the ratio of the pounds of ungulate prey
> per year for each is 1:19. When percentage waste is considered it is 1:15
> when poportionate predator size is considered it is 1:5.
> As I said...
These numbers fit my above claim, IMHO...
> > Not bad for a damned good reptile :)
Still not good enough for a dinosaur! =8-)