VENOM, HUMPS, IGUANODONS

[darren.naish@port.ac.uk]

On venomosity in mammals, Dan Bensen wrote

> only one group of mammals, the monotremes have it.  

No, some insectivorans (including shrews and solenodons) and 
primates (lorids) have neurotoxic saliva.

And on the presence of humps in mammals, Jaime wrote..

> The humps [in] *Camelus* do not conform to osteological neural
> spines, but instead are structural fatty and laminate
> tissue

Jaime is right about _Camelus_, but at least some fossil camelids 
exhibit neural spine elongation where we might predict their humps to 
be. This has been recorded for one of the giant North American 
Pliocene genera in particular - I think it may have been 
_Titanostylopus_. Elongate neural spines in the deer _Megaloceros_ 
have also been equated with the presence of a fatty hump (as depicted 
in some cave art).

Finally, Tracy mentioned a tall-spined iguanodontian from North 
America. This has occasionally been regarded as the same as _I. 
ottingeri_ from the Cedar Mountain Fm. (Yellow Cat Member), but 
seeing as _I. ottingeri_ is based on jaw fragments this can't be 
tested. Consequently, Jim Kirkland et al. note that the two could be 
different species (though I also recall an abstract where they 
described _I. ottingeri_ as a 'tall-spined iguanodontid'). In their 
new paper in _Vert. Paleont. in Utah_, Jim et al. (1999) note that 
there might even be a third _Iguanodon_ in the Yellow Cat Member, and 
that this one might be conspecific with _I. lakotaensis_. Bakker 
(1998) has opined that _I. lakotaensis_ is a primitive species akin 
to _Camptosaurus_ (in contrast, David Norman (1998) regards it as a 
junior synonym of _I. bernissartensis_) while, at SVP '99, Norman 
showed that _I. hoggi_ from the Purbeck Limestone Group of Dorset - 
previously regarded as the earliest osteological appearance of the 
genus _Iguanodon_ - is actually a camptosaur. Has anyone done a 
detailed comparison of _I. lakotaensis_ and _'I.' hoggi_ to see if 
they might be the same? I'm not being lazy: I will do this myself 
later today.

"I CAN'T TALK - I'M IN THE LIBRARY!!!!"
To be shouted very very loud on answering mobile phone.

DARREN NAISH 
PALAEOBIOLOGY RESEARCH GROUP
School of Earth, Environmental & Physical Sciences
UNIVERSITY OF PORTSMOUTH
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