Is This A Fish Otolith?

[Carl]

Okay, now we're talking. Be careful, Coco, about arguing from your first-hand experience: "Because I have not seen it, it must not exist."

Below are some examples of spherical otoliths. There are others. I saw one or two Oligocene examples on a research site in German, but there was no caption to the image.

Here are some tips to go with the image from a University of South Florida archeology site:

Examples of common fish otoliths found at archaeological sites in Florida. Images from the Florida Fish and Wildlife Conservation Commission ...thumbnail at bottom of this post... (http://www.flickr.com/photos/myfwc/sets/72157625872804969/

Otolith ID Tips:

Otoliths are small, irregularly shaped, and basically look like a million different things if you don’t know what you are looking at. That makes them a bit difficult to pick out of a screen during excavation, especially on prehistoric sites that are full of things like oyster shell!

Become familiar with the different shapes of otoliths from common species, catfish varieties are a good place to start. Their otoliths are fairly large and have a rounded shape that stands out a bit more than those of other species (see above).

Trying to decide whether something is an otolith or just a small piece of oyster shell? First, look to see if it is made up of rings, much like you would see inside a tree. If that doesn’t work, look for a sulcus or groove on one side of the otolith (look at the Black Drum and Sand Seatrout above for examples).

I think you were being a bit unfair to Coco who said "I never seen a perfectly round otolith... Generally they have at least a sharp side." This is a very well-phrased response and she never said "Because I have not seen it, it must not exist." There is a huge difference. And what are any of us doing here except arguing from our first-hand experience? It is actually all we should really trust.

[Kosmoceras]

I think you were being a bit unfair to Coco who said "I never seen a perfectly round otolith... Generally they have at least a sharp side." This is a very well-phrased response and he never said "Because I have not seen it, it must not exist." There is a huge difference. And what are any of us doing here except arguing from our first-hand experience? It is actually all we should really trust.

I have been following this topic too as it has been interesting; however, I agree that there have been some slightly unjust comments and at times quite heated moments for what in reality is just - and what should remain - an aspiration for knowledge.

[Bullsnake]

Is a pearl not a possibility?

[lissa318]

http://www.thefossilforum.com/index.php?/topic/46109-florida-eocene-ids-needed/?hl=%2Bmatrix+%2Bspheres

Not being as knowledgeable as others I shouldn't even comment. These aren't even from the same period... This post reminded me quite a bit of the spheres discussed on this one though.

[Harry Pristis]

Here is some interesting background info. Unhappily, none of the otoliths in this report resembles my object.

FISH OTOLITHS FROM THE COFEE SAND (CAMPANIAN) OF NORTHEASTERN MISSISSIPPI,
Dirk Nolf and David T. Dockery III
in Mississippi Geology, Volume 10, Number 3, March 1990.

Otolith records from Cretaceous strata are very scarce. This strongly contrasts with the many
otolith-based reconstructions of fish faunas from various Tertiary deposits. Nolf (1985) records
less than 20 valid species for the whole Cretaceous, while this number is on the order of 1,000
for the Tertiary. [This disparity] is essentially due to preservation conditions and collecting techniques.

A primary condition for otolith collecting is an unconsolidated sediment that can be sieved (sand,
silt, clay, or marl). ... [Otoliths] consist of aragonite, a metastable polymorph of calcium carbonate.
Decalcification often affects sediments to the extent that aragonite is dissolved, while the stable
polymorph calcite remains (e.g. oysters, pectinids, brachiopods, and echinoderms are preserved).
This is the case in the majority of the Cretaceous deposits in Europe, the continent where fossil otoliths
have been studied most intensively. Recrystallization of otoliths into calcite is rare, which explains their
absence in the fossil record of this period. . . .