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David Marjanovic and others have been writing about cassowary
crests. This is something we have covered at length before, so excuse
me for being repetitous. On the internal structure of cassowary
casques, David wrote....
> Solid bone. Cassowaries have even been seen digging with it. (Well,
> it could be hollow inside, but it is not fenestrated like in
Cassowary crests are tough because of their thick keratinous outer
sheaths BUT the actual bony crest is very weak and certainly not solid.
It is composed internally of hundreds of thin strut-like trabeculae
which form a honeycomb-like arrangement: the external surface is a
thin (approx. 1 mm) bony wall covered with foramina. On handling a
skull once, I accidentally put my finger through the outer wall. The
keratin sheath, which increases the crest height up to 100%, is the
BTW, cassowaries have not really been seen 'digging' with the crest:
instead they overturn soil or scrape leaf litter and soil aside.
For further discussion see the following, and the follow-ups...
"All jungles were their jungles, and no living thing could stand before
them" (dholes, not cassowaries)
PALAEOBIOLOGY RESEARCH GROUP
School of Earth, Environmental & Physical Sciences
UNIVERSITY OF PORTSMOUTH
Burnaby Road email: firstname.lastname@example.org
Portsmouth UK tel: 01703 446718