Astarte seashell

[Max-fossils]

Hi everyone,

 

Here is an astarte seashell, but I'd like to put a definitive ID on it (Genus + species). It's from the Westerschelde, NL, and ages from the Pliocene.

 

Any clues?

 

Thanks in advance! 

 

Max

[SailingAlongToo]

My best guess is somewhere between the middle Miocene and late Pleistocene but @MikeR may have a better idea.

[Max-fossils]

2 minutes ago, SailingAlongToo said:

My best guess is somewhere between the middle Miocene and late Pleistocene but @MikeR may have a better idea.

I already said it's from the Pliocene ; the note that came with it said "Pliocene; 2.5 mya" 

 

But yeah, let's hope Mike chimes in soon!

[sdsnl]

It looks rather like an Antigona sp.?

[SailingAlongToo]

See if you can match anything in these.

 

http://neogeneatlas.org/

 

http://www.malacological.org/index.html

 

[SailingAlongToo]

This might help. It has an astarte clam on left side.

 

fossil_identification_shells_miocene_maryland.pdf

[Max-fossils]

8 minutes ago, sdsnl said:

It looks rather like an Antigona sp.?

Thanks for the help! But no, Antigona doesn't seem to match really well... Antigona looks like a thinner shell, while this one is more compact. Also, the hinge of mine is a lo bigger than those of Antigona. They are of the same family though, Antigona is most probably another kind of astarte.

[Max-fossils]

15 minutes ago, SailingAlongToo said:

See if you can match anything in these.

 

http://neogeneatlas.org/

 

http://www.malacological.org/index.html

 

 

9 minutes ago, SailingAlongToo said:

This might help. It has an astarte clam on left side.

 

fossil_identification_shells_miocene_maryland.pdf

Thanks for the links!

 

The 2nd link doesn't seem to provide anything relevant...

The 3rd link does indeed show an astarte shell, but this one (the Melosia) has very pronounced ridges, as you can see in the photo. The ridges on mine are very light. So it's just another kind of astarte shell, from the same family.

On the 1st link I didn't find any match, but I do think that it's a great website, so I added it to my bookmarks. Thanks! 

[SailingAlongToo]

7 minutes ago, Max-fossils said:

 

Thanks for the links!

 

The 2nd link doesn't seem to provide anything relevant...

The 3rd link does indeed show an astarte shell, but this one (the Melosia) has very pronounced ridges, as you can see in the photo. The ridges on mine are very light. So it's just another kind of astarte shell, from the same family.

On the 1st link I didn't find any match, but I do think that it's a great website, so I added it to my bookmarks. Thanks! 

 

What are the chances your ridges are worn down or off from sediment or water erosion?

[Max-fossils]

1 minute ago, SailingAlongToo said:

 

What are the chances your ridges are worn down or off from sediment or water erosion?

Possible, but if it was the case you would see the whole shell being worn down, or at least traces of erosion, which I cannot see here...

Plus, my shell would have traveled a long way to get all the way to Europe 

[sdsnl]

23 minutes ago, Max-fossils said:

Thanks for the help! But no, Antigona doesn't seem to match really well... Antigona looks like a thinner shell, while this one is more compact. Also, the hinge of mine is a lo bigger than those of Antigona. They are of the same family though, Antigona is most probably another kind of astarte.

How thick is your shell? I have an Antigona that is 7cm long and about 1.5cm thick. I believe there are many environmental factors which may affect individual differences of thickness within the same species.

 

I suggested Antigona because it looks like your shell has vertical and horizontal ridges (though mostly worn except the bottom). Some Antigona species used to be in Periglypta, so maybe you can look into that.

[Max-fossils]

44 minutes ago, sdsnl said:

How thick is your shell? I have an Antigona that is 7cm long and about 1.5cm thick. I believe there are many environmental factors which may affect individual differences of thickness within the same species.

 

I suggested Antigona because it looks like your shell has vertical and horizontal ridges (though mostly worn). Some Antigona species used to be in Periglypta, so maybe you can look into that.

1.5 cm thick??? That's huge! Are you sure you didn't mean 1.5 cm high? Mine is maybe 3 mm thick, which for a bivalve is already quite a lot. It's about 1 cm high.

Also, do you have pictures of that shell?

My shell does indeed have slight vertical and horizontal ridges. I had a good look at both Periglypta and Antigona fossils, but with both the hinge doesn't really match well...

[Fossil-Hound]

@Max-fossils definitely not M. staminea. I've seen many of those and this doesn't resemble that. What you have appears to be Stewartia anodonta

 

See: http://www.calvertmarinemuseum.com/336/Invertebrate-Fossils

 

Another reference with some more images of the S. anodonta:

 

http://www.dgs.udel.edu/delaware-geology/bivalves-phylum-mollusca-class-bivalvia

[Max-fossils]

I just found back a book of mine about fossils from Zeeland (the Westerschelde is in Zeeland). I found a few possibilities in it:

Astartidae:

• Laevastarte basteroti
• Laevastarte ovatacostata
• Laevastarte omali
• Laevastarte mutabilis
• Astarte borealis (Pleistocene only though, so unprobable)

Veneridae

• Venus casina
• Venus verrucosa (late Pleistocene, so unprobable)
• Clausinella imbricata
• Dosinia lentiformis
• Dosinia exoleta (Holocene, so unprobable)

What do you think matches best? For me it's most probably one of the Laevastarte...

[Fossil-Hound]

@Max-fossils why not Stewartia anodonta?

[Max-fossils]

8 minutes ago, Fossil-Hound said:

@Max-fossils definitely not M. staminea. I've seen many of those and this doesn't resemble that. What you have appears to be Stewartia anodonta

 

See: http://www.calvertmarinemuseum.com/336/Invertebrate-Fossils

 

Another reference with some more images of the S. anodonta:

 

http://www.dgs.udel.edu/delaware-geology/bivalves-phylum-mollusca-class-bivalvia

Thanks for the help Jason! Unfortunately I am not convinced with Stewartia anodonta... The shape is not the same, and the hinge is also very different. Plus, the location doesn't match...

1 minute ago, Fossil-Hound said:

@Max-fossils why not Stewartia anodonta?

That's why ^ 

[doushantuo]

?

[Max-fossils]

3 minutes ago, doushantuo said:

?

Interesting!

By the way, the writer of this, Ronald Pouwer, was the previous manager of the WTKG, a great Dutch fossil organization specialized in fossils seashells (of course they also explore other domains of paleontology). Do you also know him?

[doushantuo]

No

[Fossil-Hound]

21 minutes ago, Max-fossils said:

Thanks for the help Jason! Unfortunately I am not convinced with Stewartia anodonta... The shape is not the same, and the hinge is also very different. Plus, the location doesn't match...

That's why ^ 

 

I suppose my geographic location of Maryland has thrown me a curve ball a time or two. I have seen shells very similar to what you have and am certain they are Stewartia anodonta but the hinge as you said may be different.

[Max-fossils]

Just now, doushantuo said:

No

Oh...

Well, I do suggest you to join the WTKG (you live in a basement in the Netherlands, right? ), it's really great!

[doushantuo]

I might,yet

[Max-fossils]

1 minute ago, Fossil-Hound said:

 

Roger that

Do you mean, I have to ask @Ludwigia? Sorry, I don't really know what you mean...

Just now, doushantuo said:

I might,yet

I sure hope you do 

[doushantuo]

Btw,you are beginning to get an inkling of why proteomics and karyotyping are increasingly entering bivalve taxonomy

[Fossil-Hound]

4 minutes ago, Max-fossils said:

Do you mean, I have to ask @Ludwigia? Sorry, I don't really know what you mean...

I sure hope you do 

 

Ha. I removed "Roger that." Roger in a military sense means to acknowledge or confirm. It's English for, "I understand."