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Hi Brachiopod enthusiasts. I am preparing a talk (volunteer) for the Maryland Natural History Society and am asking if anyone can help me to access some literature that would help. Stanley, Stephen M 1974 What Has happened to the Articulate Brachiopods Geological Society of America Annual Meetings Miami Florida, Clams and Brachiopods-Ships that Pass in the Night Gould, Stephen Paleobiology Vol 6 #4 Fall 1980 pp383-396 and Researchgate.net publication/229615227 Predatory Asteroids and the decline of the Articulate Brachiopods Donovan, Stephen K 10/2007.  Just noticed what's with all these Stephens and brachiopods?

Finally does any one have any info on the proportion of articulate brachiopods that used pedicles versus just laying on the bottom or using spines?

Any specific help would be greatly appreciated. If anyone wants to comment or make suggestions about what to include i would welcome them. The talk is titled Brachiopods and Bivalves: Two Look-alikes with different approaches to filter feeding. It is geared for curious individuals to stimulate interest in both groups and includes fossil and modern examples. Thanks for taking a look and any comments you would like to make.

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https://www.jstor.org/stable/27670383?seq=1#page_scan_tab_contents This link contains a publishing by Benjamin F. Dattilo, notably going over how Sowerbyella may have been able to swim like a scallop, such as if one was caught underneath the mud from a storm, it may have been able to escape! Just something I thought that was unique. For the site you'll have to make an account where you'll be able to read six articles for free per month. I found this article from reading A Sea Without Fish: Life in the Ordovician Sea of the Cincinnati Region by David L. Meyer and Steven M. Holland. Chapter 8 deals exclusively with brachiopods, both articulate and inarticulate. Though brachiopods are often mentioned throughout the book, such as how their shells were instrumental in the growth of other biota and building reef systems. I've personally learned a lot from this book, I know your focus is of brachiopods, but I'd also recommend it for anyone who's interested in the Ordovician and the Cincinnati series.

 

Also, I'm sure @Tidgy's Dad could help you, he's the main brachiopod man of the forum.

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@CSimpson176Thanks for what sounds to be an interesting article. I will check it out. 60+ years ago I went to school in Cincinnatti which is partly why I love fossils so that sound like an interesting book for future reading. Thanks again.

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I'm afraid I don't have any of the papers mentioned. 

And what the proportion of articulate brachiopods with pedicles compared to those without is very complicated and also is dependent on when. In the present day, very few articulates don't have a pedicle, the members of the order Thecideida, while in the early to middle Cambrian the important classes Obolellata and Kutorginata which comprised a high percentage of brachiopods at that time had no pedicle. Particularly in the Devonian - Permian many strophomenids had no pedicle but were an important part of the brachiopod fauna as were the spiriferids, some of which had a pedicle when young but lost it as they matured, do we count these or not? 

I can't think of any Mesozoic brachiopods with no pedicle off the top of my head, other than the Thecidedides that were a very minor part of the brachiopod fauna.

Sorry, not much help I'm afraid.:(

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@Tidgy's Dad  Actually you were very helpful. :thumbsu:Agreed it is complicated, time variable and even varies by the age of the animal. If I read you right, from Mesozoic on all had pedicles. Any thoughts on what was the function/purpose the various brachiopod shell shapes and ornamentation had? In bivalves, it aided or hindered in its ability to burrow but if I understand correctly, there were no burrowing brachiopods. What caused the major decline in brachiopods in the Mesozoic to today. Clearly the Permian extinction impacted them more than bivalves. But they failed to recover. One paper suggests that predation by a new type of starfish limited their recovery. Other reading seems to suggest that the size and positioning of the lophophore limited its shell forms to adapt to different habitats. Any thoughts?  Thanks again for taking the time to respond. Any material you would recommend would be appreciated.

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The order Thecideida are articulates with no pedicle which first appeared in the Triassic and are still around today. Indeed, they are a group of brachiopods that are perhaps becoming more varied and successful, though still a minor group. 

The primary function of any brachiopod shell was/ is protection, as a brachiopod is otherwise utterly defenceless (though articulates are said to taste horrible and it seems that vertebrates and arthropods generally avoid them, though starfish, as you've mentioned, will eat them!), but the shell is also a support for the brachidium (where present) and is the fixing point for the muscles etc. At least one modern form displays sexual dimorphism as the female has a bulge where the brood pouch is located and the Devonian Uncites is another that displays this feature. Palaeozoic forms have far more variety in shell morphology with spines and ridges, a greater variety of shapes and so on that provided a much greater range of function and purpose. Only the linguliids today are true burrowers, but some of the articulate forms in the past at least nestled into soft substrates or used the shell as a 'snowshoe' to not sink into it. 

The Permian extinction effected both the bivalves and the brachiopods very seriously, but the brachiopods were hardest hit. Thayer, (1979) concluded that immobile suspension feeders living on soft substates declined and never fully  recovered due to infaunalization and bioturbation. Gould and Calloway (1980) show that  both bivalves and brachiopods are increasing in diversity since the Permian extinction, but bivalves have been doing it quicker. Payne et al (2015) suggest that the reason is the higher metabolic rate of bivalves since the Ordovician led to the change in fortunes of the two groups when the bivalves were given the opportunity following the Permian. Payne et al add that it is a mistake to concentrate on a groups abundance and taxonomic diversity, rather than on biological processes, as this leads to plausible but finally misleading conclusions about macroevolution.   

I will have a look and see if i can find some papers later as I am currently watching the cricket.:)

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@Tidgy's DadAppreciate your taking the time for such a comprehensive response. Thanks. Hope it was an exciting game. We need a brachiopod emoticon!

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Yes, the cricket is interesting enough if not too exciting just now. 

While they're on hydration break, here's one that contains lots of useful little bits, particularly some pertaining to the Permo-Triassic extinction and subsequent recovery of brachs and bivalves.

http://paleopolis.rediris.es/BrachNet/ANNONCES/BC/IBC-abst/7IBC-abst.pdf

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