Are these crinoid columns?

[RobertBlackBeard]

From what I learned from my other post, I can only assume that these are also crinoid columns, just smaller. Would I be correct? Also I found these in the same creek in Oklahoma like most of my other findings.

[Herb]

yes they are, nice ones

[Darktooth]

Yes, good finds!

[belemniten]

Nice !

[abyssunder]

Yes, you are correct. Crinoid columns. In the center of each columnal is a little hole called lumen.

[doushantuo]

crinoid anatomy:

http://www.bioone.org/doi/pdf/10.2108/zsj.14.753

Seilacher/Haude on ecology:

http://cdn.palass.org/publications/palaeontology/volume_11/pdf/vol11_part2_pp275-282.pdf

Edited May 25, 2016 by doushantuo

[doushantuo]

Eleaume et al(ZOOM.):

nice neontology ,columnal ontogeny

https://www.researchgate.net/publication/261440698_A_new_type_of_stalk_articulation_in_the_sea_lily_genus_Vityazicrinus_Echinodermata_Crinoidea_and_its_ontogeny

Edited May 25, 2016 by doushantuo

[Harry Pristis]

I don't think I've ever encountered the term "column" used to describe a crinoid stalk.

The term "columnal" is commonly used for the individual elements of the stalk.

Here's an example of the usage from one of doushantuo's links:

"The stalk increases in length mostly by addition of new columnals below the theca and into the proxistele. During ontogeny, each columnal is pushed away from proximal to distal along the stalk main axis."

from: A new type of stalk articulation in the sea lily genus Vityazicrinus (Echinodermata, Crinoidea) and its ontogeny

[Guguita2104]

I agree with crinoid columnals.

Nice ones .

Regards,

Guguita

[doushantuo]

i stand corrected,Harry Pristis.

********beet-red in the face**************

*****puts on Duncehat*****

Edited May 25, 2016 by doushantuo

[Harry Pristis]

i stand corrected,Harry Pristis.

********beet-red in the face**************

*****puts on Duncehat*****

The correction was not directed at anyone in particular -- don't be embarrassed.

Common language is dynamic, while scientific terminology is not. The many newbies

who will eventually read this thread should not pick up this minor error. You kewl

with that?

[abyssunder]

"The crinoid column is also called a stem or stalk. The stem is made from disc-shaped pieces of endoskeleton which are stacked upon each other and are hollow in the middle. They are held together by ligaments which decomposed rapidly after death. The hollow shapes inside of the discs include: elliptical, circular, pentagonal, and star-shaped. Column discs which are square-shaped have 5 holes in them. (...)
The stem is constructed from a biomineral complex made from calcium carbonate crystals in a sponge-like microstructure. The three-dimensional microstructure is called stereom. (...)
Some species have special appendages emerging from the bottom of the calyx or along the stem. These appendages are not used for feeding, but are types of holdfasts. They are called cirri. (...)
The calyx is a cup-shaped body part which contains the u-shaped digestive system and the organs for reproduction. Five sided, calcareous plates create the lower cup of the calyx. " https://www.fossilera.com/pages/about-crinoids

" Column - Series of segments composing stem; excludes holdfasts.
Columnals - Individual ossicle (calcified segment of skeleton) of crinoid stem.
Holdfast - Any structure at distal extremity of column serving for fixation. " http://www.mcz.harvard.edu/Departments/InvertPaleo/Trenton/Intro/PaleoPage/Terminology&Morphology/Terminology&Morphology.htm

Basic crinoid morphology is labeled on the sketch below. Image from Ubaghs, 1978

" Crinoids are either sessile, attached to the substrate by a skeletal column, or they are planktonic. " http://palaeo.gly.bris.ac.uk/palaeofiles/fossilgroups/crinoidea/page2.html

" Crinoids are known as sea lilies because they live on a stem and have a flower-like body. The most common crinoid fossils are the individual button-like plates that made up the stem. " https://www.uky.edu/KGS/fossils/crinoid.htm

Source: Figure 21, page 17, “Common Fossils of Pennsylvania, Pa. Dept. of Conservation and Natural Resources, Bureau of Topographic and Geologic Survey)

Source: Maryland Geological Survey E.S. No. 4, p. 38, Fig. 35

Edited May 25, 2016 by abyssunder

[Auspex]

I am perhaps technically in error in calling a stack of columnals a column, but stem and stalk both carry a botanical connotation which is misleading, just like "sea lily". Lotsa' folks in 'net-land' don't know that crinoids are animals.

[Harry Pristis]

I stand corrected. Abyssunder has demonstrated that at least one original source (Moore, et al., 1978) preferred "stem" and "column" in describing a species of crinoid.

[tmaier]

It would be nonsensical to use the adjective form "columnal" without it referring to a column. If we drop "column, we need to drop the adjective, too. And like Auspex mentions, I prefer the mental image of a column, like the Romans made, consisting of columnal segments. It is very descriptive, and "stalk" is less so.

[fifbrindacier]

"The crinoid column is also called a stem or stalk. The stem is made from disc-shaped pieces of endoskeleton which are stacked upon each other and are hollow in the middle.

It would be nonsensical to use the adjective form "columnal" without it referring to a column. If we drop "column, we need to drop the adjective, too. And like Auspex mentions, I prefer the mental image of a column, like the Romans made, consisting of columnal segments. It is very descriptive, and "stalk" is less so.

Speaking of pieces of endoskeleton stacked upon each other really recalls me clearly the Roman columns made with pieces of stone stacked upon each other. It is a good image.

[doushantuo]

I THINK a crinoid stem is a "stele".

[BobWill]

It would be nonsensical to use the adjective form "columnal" without it referring to a column. If we drop "column, we need to drop the adjective, too. And like Auspex mentions, I prefer the mental image of a column, like the Romans made, consisting of columnal segments. It is very descriptive, and "stalk" is less so.

Don't forget this is English where so many words have two meanings. Columnal the adjective does refer to any column but when it's used in reference to a crinoid stem section it's a noun. https://en.wiktionary.org/wiki/columnal

Robert, yours aren't necessarily small. They come in all sizes. Some places where I collect they are all even smaller than yours. Posters probably often show their biggest to impress us

Edited May 26, 2016 by BobWill

[fifbrindacier]

From what I learned from my other post, I can only assume that these are also crinoid columns, just smaller. Would I be correct? Also I found these in the same creek in Oklahoma like most of my other findings.

Robert, yours aren't necessarily small. They come in all sizes. Some places where I collect they are all even smaller than yours. Posters probably often show their biggest to impress us

I have some crinoid stems with only one or two segments and some columns are very little and thin because of their species.