Ammonite paleobiogeography during the Pliensbachian–Toarcian crisis (Early Jurassic) reflecting paleoclimate, eustasy, and extinctions
Guillaume Dera, Pascal Neige, Jean-Louis Dommergues and Arnaud Brayard, 2011
Ammonite paleobiogeography during the Pliensbachian–Toarcian crisis (Early Jurassic) reflecting paleoclimate, eustasy, and extinctions
Guillaume Dera, Pascal Neige, Jean-Louis Dommergues and Arnaud Brayard, 2011
Kevin
Transient metazoan reefs in the aftermath of the end-Permian mass extinction
Not a lot about cephalopods, but part of our study.
Kevin
Hi Monty,
Do you still have a copy of the didy jaws article?
Please email if you do.
thanks
Alan Schaffert "singaya"
schaffert@comcast.net
Singaya, I'm sorry to report that Monty passed away in 2010. Here is a blog post about it.Originally Posted by singaya
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On it's way
Kevin
Our article "EARLY EVOLUTIONARY TRENDS IN AMMONOID EMBRYONIC DEVELOPMENT" is online. It is still the accepted manuscript, but this should change in the next months.
Hope you like it!
Kevin
Excellent paper Kevin! So interesting to see this story unfold and to actually understand it's conclusion's (I only have a half dozen terms to look up).
Welsh Holothurian Bed a nice discussion of what may be Nautiloid Coprolites.
A reference from DWhatley, and a thank you to TONMO Forums in the Acknowledgments. I've been searching for the thread this relates to with no luck... can anyone remember?
Kevin
I'll help you find the thread if you ell me how my name got involved
I DID read this line:
as:It is adjacent to a housing estate, and although the section is in need of clearance, some outcrops are easily accessible.
It is adjacent to a housing estate, and although the section is in need of clearance, some octopuses are easily accessible.
Three times before I read it correctly (it kept reading oddly so I reread it)I was pretty sure there were not octopuses in the Ordovician even with the lack of soft tissue preservations.
Last edited by DWhatley; Mar 13, '12 at 1:21am.
"D"
"Of all the things that I have lost, I think I miss my mind the most".
Under the heading Trophic RelationshipsA nautiloid producer of these mitrate plate concentrations is most likely. We have been unable to find any references for what nautiloid coprolites would be expected to look like, or any information on modern nautiloid faeces. Zangerl et al. (1969) reported structures that they interpreted as nautiloid coprolites, without providing any definite evidence for this view. Structures have been reported from the Soom Shale that may be the coprolites of nautiloids (Aldridge et al., 2006), but this interpretation is based only on the presence of nautiloids within the deposit, rather than any characteristics of the structures themselves. Modern nautiloids do not produce recognisable pellets in aquaria, instead producing amorphous or stringy material (Bruce Carlson, personal commun., 2011), and octopus also do not produce recognisable pellets; internal tissues of prey are often liquefied using venom, leaving mineralised plates intact (D. Whatley, personal. commun., 2011). Many modern octopodes are known to produce 'middens' of shelly debris (e.g., Vincent et al., 1998), as they do not ingest hard sclerites, and their foraging behaviour tends to focus on the most common available prey species (Leite et al., 2009). The absence of discrete pellets associated with the midden-like accumulations in the Holothurian Bed therefore suggests a nautiloid rather than arthropodan predator. While interpreting the behaviour of extinct taxa on the basis of their extant distant relatives must be done with care, in this case it does show that cephalopods represent a plausible producer of these concentrations of mitrate debris.
ACKNOWLEDGMENTS... D. Evans for pointing us in the right direction for the nature of nautiloid droppings, and the participants at www.tonmo.com cephalopod forums for confirming his suggestions...
Kevin
I am sure I have mentioned the empty, intact shells (but you can count on more words and less formality) but I'll be darned if I can place the discussion. I do think it is cool though (we have no giggle icon). Wouldn't you know I would get a reference discussing octo ... scat
By George, I think I found it
http://www.tonmo.com/forums/showthre...ntology-paper)
The TONMO referer may be GPO87 but the first initial would be wrong.
Last edited by DWhatley; Mar 14, '12 at 7:21am.
"Of all the things that I have lost, I think I miss my mind the most".
OH my! I guess it is just coincidental that the period for these Oman ammonids is called the Smithian period
"Of all the things that I have lost, I think I miss my mind the most".
Just coincident, Not "Hajarian"
Kevin
HaHa! I just saw this.
Apparently "Tozer (1965, 1967) named the Smithian for two ammonoid zones in the Blind Fiord Formation on Smith Creek, Ellesmere Island ... "
Smith Creek was named after James Perrin Smith, a famous Triassic ammonoid worker in the early part of the last century. There is also creeks named Spath Creek, Diener Creek and Greisbach Creek on Ellesmere, all named after ammonoid workers and all type localities for Early Triassic stratigraphy.
Of course we are all more familiar with another "Smith"
Kevin
The Color Patterns of Fossil Cephalopods and Brachiopods, with Notes on Gasteropods and Pelecypods
http://deepblue.lib.umich.edu/handle/2027.42/48186
one of the best papers ive read.
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