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CASSOWARIES AND APOLOGIES



THIS MESSAGE IS ENTIRELY ABOUT AVIAN DINOSAURS. YOU HAVE BEEN WARNED.

First, apologies; the Black thrush (blackbird is too ambiguous, some would say)
is Turdus MERULA. Sorry for f.. f. fowling up. And there's no such corvid as
CORVUS CORVUS, I was thinking of Corvus corone. One if its subspecies is C. c.
corone, which is where I got confused (repetitive name). I could have been
muddled by C. corax, the Raven. (Where are you Skip?)

CASSOWARIES

I thought it would be better to list this, as it'd take too long to mail you all
personally. Thanks for the interest (to those applicable).

TAXONOMY

Cassowaries (Cs from here on) are today represented by 3 species, all close
relatives and fairly similar, of the genus Casuarius. 
Single-wattled c  (North Aust., New Guinea?)
Double-wattled c  (can't remember.... N.G.?)
Dwarf c/Moruk/Bennett's c  - New Guinea (and ?New Britain)
 - billed as 'the meanest bird alive'

They are distinct enough from other ratites to get their own family, the
Casuaridae. Together with emus (the Dromaiidae) they are grouped in the
Casuariformes, but some authors think that all ratites should belong in a single
Order called Struthioniformes (traditionally reserved just for ostriches).
Sibley and Alquist think that Cs and emus are closer than usually thought, and
that both should be treated as subfamilies of the same family (the Casuaridae).
[Ratites need a good cladistic analysis, something I'd like to do when I'm
professional - if no one beats me to it that is] Cs and emus share 'loose, fur-
like feathers' and, instead of a tridactyl carpometacarpus, have only a single,
hyperelongated digit with a long claw. Ornithologists regard this digit as no.
3, but they are relying on a flawed conclusion of some embryological work and,
in fact, it is digit 2. Emus have 20 neck vertebrae, Cs 18 or 19 (I've forgotten
my notes and thus might be a bit wrong with some details).

Cs are known from the Pliocene onward, emus from the late Miocene. Obviously
this clade evolved in the Australasian region, or maybe it was more widely
distibuted previously and later became restricted to this area. Fossil species
are near identical to modern ones, and hence Cs have been regarded as 'living
fossils'. Argh! The evolution of ratites is a real mess, and really complicated
and subject to opinion. Patagopteryx shows that they HAD evolved during the
Cretaceous, rebuking some of Fedducia's ideas.

CHARACTERISTICS AND BEHAVIOUR

Cs have black, shiny plumage which hangs loosely, like long fur. Unlike those
of emus, the feathers are not double-shafted. This loose pelage is believed to
help them withstand abrasion against dense vegetation, which, it is alleged, the
bony casque does too. The 'best' thing about them, I suppose, is how damn mean
they are. They still have wing feathers, but they have become 5 or so hollow
shafts without barbs that are deadly sharp and can be used as weapons. On digit
2 of the foot (no digit 1) they have an enlarged, very sharp ungual. In the
Moruk, or Pygmy C (from New Guinea highlands), this is 10 cm. long. The birds
can kick (obviously) and can even do a hop-and-double-strike, slashing an
opponent or, in the case of a soft-bodied human, effecting a disembowelment.
They are known to have killed several people. Drom. workers take note (most
already have). Notes in field guides (Simpson and Day, the best field guide ever
written, says:) "very aggressive, do not approach". Elsewhere I read that they
are shy. Hmm. 

I read all possible sources in a search for the truth about sexual dimorphism
amongst these animals. At least two said "sexes similar", but it does actually
seem that females are a bit bigger (one source said much bigger) and somewhat
more brightly coloured. Females also have bigger casques. Emus also have larger
females, as do birds of prey (including some owls), baleen whales, tyrannosaurs
and the binturong. Male Cs look after eggs and babies, as do male emus, without
help from females, and this is probably something to do with it. Both males and
females have the same adornment of wattles, however. It can be hypothesised
that, initially, males were brightly coloured and more adorned but are now being
'usurped' by females, because of the new baby-care system these birds have
evolved.

The casque, superficially resembling that of Corythosaurus and Oviraptor, is not
solid, but is hard and enlarged by horn. Many sources state that it is used to
push vegetation aside (consequently the same use has been postulated for
hadrosaur crests), but recently a zoo specimen was seen to use the casque to
turn soil over, revealing food. It therefore seems possible that it is a kind
of tool. New Guinea natives don't classify Cs amongst birds and bats, but give
them their own group because of their 'furry' feathers and their hard skulls.

Cs are the only large surviving forest-dwelling ratites (ignoring claims of
surviving moas) and, as such, give a valuable insight into lifestyles of big,
forest-dwelling birds. They are mainly frugivorous, swallowing fallen plums etc.
whole, but also eat small vertebrates and even carrion! They can run as fast as
emus (ask Jim Farlow just how fast that is), but tend not to because of their
forest habitat (they're rarely out in the open). They are also powerful
swimmers, but that's no surprise. Most individuals live a solitary life, but
some hang around in small bands or couples. I think they're cool.

DARREN 'Mineralogy and crystallography exam in 1 hour 45 mins' NAISH