Fossils B/C

[JoJoKeKe]

This is a silly question- but are those in Class Asteroidea sessile or benthic? I know that most echinoderms are sessile, but any extra information is helpful.

Thank you!

[Magikarpmaster629]

This is a silly question- but are those in Class Asteroidea sessile or benthic? I know that most echinoderms are sessile, but any extra information is helpful.

Thank you!

Benthic. Think of what kinds of things they eat- they need to move around.

[GoofyFoofer]

This is a silly question- but are those in Class Asteroidea sessile or benthic? I know that most echinoderms are sessile, but any extra information is helpful.

Thank you!

Benthic. Think of what kinds of things they eat- they need to move around.

Don't all echinoderms move?

EDIT: *nearly

[JoJoKeKe]

This is a silly question- but are those in Class Asteroidea sessile or benthic? I know that most echinoderms are sessile, but any extra information is helpful.

Thank you!

Benthic. Think of what kinds of things they eat- they need to move around.

Don't all echinoderms move?

Well, aren't Crinoids and Blastoids sessile? My knowledge on the echinoderms is lacking, so I'm trying to fill in the blanks. Any help is greatly appreciated.

(In addition, could anyone concisely explain to me the differences between mollusk and brachiopod shells directly relating to shell structure?)

[Magikarpmaster629]

(In addition, could anyone concisely explain to me the differences between mollusk and brachiopod shells directly relating to shell structure?)

This isn't always consistent- a problem with morphological taxonomy, but this is generally how it is put: (also when you say mollusc I assume you mean bivalve)

Imagine a plane cutting across the ridge separating the shell in both the brachiopods and the bivalves. There is no problem with this, seeing how both groups have a rough line on the border of each valve. But the symmetry for this is inconsistent; the bivalve is (in general, but not always) symmetrical on both sides of the plane, however the brachiopod is not (again, not always the case). Now imagine twisting the plane 90 degrees along the y-axis, so it cuts each shell in half from a top-down view. Now the brachiopod is symmetrical, and the bivalve is not (you'll notice Genus Pecten on the list does not follow this rule- it is symmetrical both ways).

[HeavyHitter406]

Hey guys-

So, I'm doing Fossils for the first time this year; forgive me if my subsequent question is stupid. I've been doing descriptions of each of the fossils and just got to the genus Lingula under the class Inarticulata. However, when I look up the fossil, it said that this class had been superceded and Lingula actually belonged to the Lingulata class. Am I missing something? Using an old copy of the official list? Thanks a bunch.

[gryphaea1635]

Hey guys-

So, I'm doing Fossils for the first time this year; forgive me if my subsequent question is stupid. I've been doing descriptions of each of the fossils and just got to the genus Lingula under the class Inarticulata. However, when I look up the fossil, it said that this class had been superceded and Lingula actually belonged to the Lingulata class. Am I missing something? Using an old copy of the official list? Thanks a bunch.

Actually that's a decent question... well on wikipedia it says that there are 3 "ways" of grouping brachiopods and that using Articulata and Inarticulata (based on hinge type) is the "traditional classification" while Lingulata is part of another version of classification based on shell composition. So I guess Lingula can belong to multiple classes in a way. (here see this https://en.wikipedia.org/wiki/Brachiopod#Taxonomy)

You should just go with Inarticulata

[Magikarpmaster629]

Hey guys-

So, I'm doing Fossils for the first time this year; forgive me if my subsequent question is stupid. I've been doing descriptions of each of the fossils and just got to the genus Lingula under the class Inarticulata. However, when I look up the fossil, it said that this class had been superceded and Lingula actually belonged to the Lingulata class. Am I missing something? Using an old copy of the official list? Thanks a bunch.

Actually that's a decent question... well on wikipedia it says that there are 3 "ways" of grouping brachiopods and that using Articulata and Inarticulata (based on hinge type) is the "traditional classification" while Lingulata is part of another version of classification based on shell composition. So I guess Lingula can belong to multiple classes in a way. (here see this https://en.wikipedia.org/wiki/Brachiopod#Taxonomy)

You should just go with Inarticulata

If you have a field guide, use its classification. Event supervisors and field guides tend to use traditional classification, and wikipedia does not.

[Unome]

Hey guys-

So, I'm doing Fossils for the first time this year; forgive me if my subsequent question is stupid. I've been doing descriptions of each of the fossils and just got to the genus Lingula under the class Inarticulata. However, when I look up the fossil, it said that this class had been superceded and Lingula actually belonged to the Lingulata class. Am I missing something? Using an old copy of the official list? Thanks a bunch.

Actually that's a decent question... well on wikipedia it says that there are 3 "ways" of grouping brachiopods and that using Articulata and Inarticulata (based on hinge type) is the "traditional classification" while Lingulata is part of another version of classification based on shell composition. So I guess Lingula can belong to multiple classes in a way. (here see this https://en.wikipedia.org/wiki/Brachiopod#Taxonomy)

You should just go with Inarticulata

If you have a field guide, use its classification. Event supervisors and field guides tend to use traditional classification, and wikipedia does not.

I'd agree with this (although definitely try to be aware of specifically who your event supervisor is e.g. a professor, the coach of a team, etc.). However, it's good to know both names because sometimes you can tell which one the test writer is looking for based on the context of the question.

[HeavyHitter406]

Actually that's a decent question... well on wikipedia it says that there are 3 "ways" of grouping brachiopods and that using Articulata and Inarticulata (based on hinge type) is the "traditional classification" while Lingulata is part of another version of classification based on shell composition. So I guess Lingula can belong to multiple classes in a way. (here see this https://en.wikipedia.org/wiki/Brachiopod#Taxonomy)

You should just go with Inarticulata

If you have a field guide, use its classification. Event supervisors and field guides tend to use traditional classification, and wikipedia does not.

I'd agree with this (although definitely try to be aware of specifically who your event supervisor is e.g. a professor, the coach of a team, etc.). However, it's good to know both names because sometimes you can tell which one the test writer is looking for based on the context of the question.

Thanks for the responses guys, I'll write both down and include a brief explanation as to why it is how it is. Thanks again