Giant Shells in Peru

Original Article: "Giant Shells in Peru's Andes" by Enrique Raul Pando Castro
( Email: )
Originianl article which could be found on George Sangiologlu's site does not seem to exist at this time. ( )


Discussions on these findings by Conch-L members:
Visit the Conch-L Archives

April 21, 2001:

Dear friends,
Mr. Enrique Raul Pando Castro had send me very interesting photos of the giant fossil from Peru's Andes, and the following request:
I hope you will enjoy these snapshots we just want to know who can help us to send them to America for exhibitions.
Enrique Raul Pando Castro
Av. Universitaria 1658 Lima 07

Please enjoy the photos and more information, at: "Site address no longer valid"

Best regards.
George Sangiouloglou ( )


April 21, 2001:

Hello Conch-L,

A month ago, George Sangiouloglou posted a piece about a discovery of giant fossil "oysters" high in the Andes Mountains in Peru. Recently our local shell club printed a picture of the find in the club
newsletter. I have posted it for anyone who would like to take a look. The picture quality is not great (scanned from a halftone, which was probably copied from a newspaper), but still interesting I think. See image below

Paul M

April 21, 2001:

Wow! Now those are oysters! Thanks for posting it, Paul.



April 21, 2001:

Can anyone confirm that these are truly fossils, and not just odd-shaped rocks that look like "oysters?"

Actually, just out of view of the camera were foot-long fossil lemon wedges and neolithic pottery gallon buckets of cocktail sauce.


April 21, 2001:

Andrew Vik


To what group of oysters do these fossils belong?   And why would anyone doubt that they are fossil oysters?
We have bivalves of that size (Tridacna) in the modern world.
Oh well, there are people who doubt just about everything from the holocaust to the Apollo Moon explorations.

Yours, Andrew V.


April 21, 2001:

I believe that these shells are giant brachiopods.
Does anyone else think so?

James M. Cheshire


April 22, 2001:

One should always be skeptical in regards to heresay information. The lack of thought leads to people sending known urban legends and bogus virus alerts to others. In the case of the "giant oysters." it
appears that "oyster" may be the wrong term.

Bill Frank
1865 Debutante Dr.
Jacksonville, FL 32246-8645


April 24, 2001:

The structures are almost surely concretions and certainly not inoceramids. Although inoceramids have all the features David Campbell discussed, the large members of the family are all extremely flat forms ; ie, they could never the degree of inflation shown in the pictures.

Cheers, Peter Harries
University of South Florida
4202 E. Fowler Ave., SCA 528
Tampa, FL 33620-5201


April 22, 2001:


the thought crossed my mind, first becuse the growth lines seems to be too simetrical for a bivalve. And then, there are two photos, in Sangiouloglou's site, the 6th and the last, and they seem to depict the posterior side of brachiopods, not the dorsal side of bivalves.

But pictures aren't that clear...



April 22, 2001:


Wouldn't brachiopods of that size be a greater discovery than giant oysters?
I have never heard of any even half that size, although I don't read about that phylum very often.

Andrew V.


April 22, 2001:

We have about 1500 species of fossil brachs in our collection ...have sudied them from all ages and all locations ...if those are brachs then we will EAT them ....
On a serious note ...IF I had to bet money. ...fairly sure the photos are of non-organic concretions. Have seen similar concretions. These can be formed from a variety of geologic occurences. BUT ...never say never (except to them being brachiopods).
Anyways, lots of FUN!!



April 22, 2001:

OK. Now you've done it! Everyone knows that there are no bi-valves in the Andes. And everyone except my mother knows there are no brachiopods at that elevation. Well, what does that leave??? Of course!!! You have discovered the eggs of Flying Pigs. They lay them in the Andean Summer.
Then they come North. After which they return to the Andes in time for the eggs to hatch. Gee, I thought everyone, except my mother, knew that.



April 22, 2001:

Dear Listers,

Thus far, Art's construct is the first to break the plausibility barrier (at least among biotic explanations).



April 22, 2001:

Dear George,I looked at the interesting photograhs of the "giant shells from Peru". I have seen almost the same concretions in the Jura exposed at the coast of Cap Griz Nez in northern France. Here the beach is full with con I think I only have a diapositive of them, so I can't sent you a photograph.

Martin C. Cadee, The Netherlands


April 23, 2001:

They look like concretions to me as well. Plus, they are not really that big. The two people in the photo are midgets.

G. Thomas Watters, PhD
Curator of Molluscs
Museum of Biological Diversity
Department of Evolution, Ecology and Organismal Biology
The Ohio State University
1315 Kinnear Road
Columbus, OH 43212 USA


April 23, 2001:

If the structures are indeed biogenic and not concretions (hard to tell from the photos), then they are almost certainly inoceramid bivalves. I have seen inoceramids of about that size from the Cretaceous Pierre Shale in Colorado. Inoceramids are traditionally considered close relatives of Isognomon, Pteria, etc. and range from the Permian to the upper (but apparently not uppermost) Cretaceous. However, Paul Johnston and coauthors have recently suggested that they represent a distinctive extinct subclass, related to the Paleozoic "cryptodonts" like Praecardia, Slava, etc. They typically occur in dark shales (which seemed plausible from the photos). The hinges are edentulous, with numerous ligament pits like Isognomon. The shells often have broad concentric ribbing. The ligament is somewhat unusual. The outer shell layer consists of large calcite prisms that are distinctive in the sediment even after the shell has crumbled away. Inoceramids and their kin may have been chemosymbiotic. A specimen with possible traces of gill supports suggests a somewhat peculiar anatomy.

George's web page mentions Plagiostoma gigantissima as an apparent guess by the discoverer. This is a European Jurassic limid (file clam), much smaller than these forms, and lacks the concentric sculpture of these specimens.

The largest known brachiopod is indeed much smaller than these.

Dr. David Campbell
"Old Seashells"
Biology Department
Saint Mary's College of Maryland


April 24, 2001:

The structures are almost surely concretions and certainly not inoceramids. Although inoceramids have all the features David Campbell discussed, the large members of the family are all extremely flat forms ; ie, they could never the degree of inflation shown in the pictures.

Cheers, Peter Harries
Dept. of Geology
University of South Florida


April 27, 2001:

They are not fossils. They are most likely calcareous concretions from what biostratigraphers call "sedimentary condensed sections"; I have been able to see these usually giant concretions embedded in dark shales in most geologic sections of the Cretacic/ Tertiary age boundary in Eastern Venezuela where geologic correlations to find oil reservoirs are usually done; the shales - and not the concretions- usually contain a lot of deep water fossil remains, such as forams, nanoplankton and mollusks, sometimes it is possible to find large, flat inoceramids which are bioindicators for age and basin depth correlation of the stratigraphic unit.
Amanda Diaz


September 03, 2003

Why can't they be just what they seem to be Giant Oysters or Clams left over after the great flood the bible and hundred of other cultures talk about 4300 years ago.
they find tropical plants in Alaska and Siberia frozen dinosaurs and mammoths so why not oysters in the Andes
Jeff Nelson

If you would like to add your ideas and comments on these giants,
Please write to me: Avril Bourquin
Please put Giant Shells in Peru on the subject line.