[WANTED] Eurypterid or Eldredgeops

[Fossil-Hound]

I have a decent collection of trilobites (Phacops, Elrathia Kingi, Perenopsis) along with a new Eoredlichia that's being shipped directly from China. I also have a large assortment of sharks teeth (Bull, Sand Tiger, Tiger, Snaggletooth) from the Calvert Cliffs Maryland area, a pristine condition Ecphora (Maryland state fossil), a saltwater crocodile tooth, turritella's, quartz horned corals (W New York), porpoise teeth, shark vertebrae, dolphins bones and vertebrae fragments, and numerous other fossils.

[TyrannosaurusRex]

Unfortunately, as i am sure you know, those fossils run well into the hundreds and even thousands. And there is a pretty high demand for them.

I've seen them for sale for over 2 thousand dollars. 

 

If on the other hand, you wanted to go find one yourself, New York is only a 5 hrs drive from DC.

 

This may be of some use.

http://www.fossilmuseum.net/fossils/Chelicerata/Eurypterus-remipes/Eurypterus.htm

[FossilDAWG]

Perhaps you are not aware that Eldredgeops is a new name for what used to be called Phacops?

 

Don

[DevonianDigger]

5 hours ago, FossilDAWG said:

Perhaps you are not aware that Eldredgeops is a new name for what used to be called Phacops?

 

Don

 

Not entirely true. The Phacops rana is now Eldredgeops rana, but Phacops is still very much its own genus, i.e. Phacops latifrons.

 

Great post about it here courtesy of @GerryK: 

 

[FossilDAWG]

2 hours ago, DevonianDigger said:

 

Not entirely true. The Phacops rana is now Eldredgeops rana, but Phacops is still very much its own genus, i.e. Phacops latifrons.

 

Great post about it here courtesy of @GerryK: 

 

That is true and I am aware of the taxonomic basis for dividing up Phacops and the need to erect new genera.  I will admit that when jsnrice said they already had Phacops I assumed they were talking about having a specimen of one of the common North American Hamilton Group trilobites.  It seems to me that if they are looking for an Eldredgeops and say they already have a Phacops, and they are aware of the extremely close nature of the two genera, they would have indicated that.  Someone would have to really be into trilobite taxonomy to intentionally go looking for comparative material of the two genera.  Someone with that level of sophistication would probably also be aware that the Wheeler Shale trilobite commonly sold as Peronopsis interstricta has been reassigned to Itagnostus interstrictus, and they would not have misspelled Peronopsis.  Again I am making an assumption, based on the fact that actual Peronopsis is vastly more difficult to obtain from commercial sources compared to Itagnostus interstrictus, and it is also not easy to collect personally in North America, as only P. amplaxus from the House Range and a few species from the Manuels Brook/Avalon Peninsula area of Newfoundland are retained in the genus.  Pernonopsis amplaxus is not common, and the Manuals Brook site has been closed to collecting form many years.  Also, a sophisticated trilobite collector would know that the "kingi" in Elrathia kingi should never be capitalized.  All these issues (using Phacops for Eldredgeops, "Perenopsis" (misspelled) for Itagnostus, capitalizing "kingi") are very common mistakes made by commercial fossil dealers, so I assumed that jsnrice either purchased their specimens, or IDed them based on fossil dealer web sites.

 

So, I assumed that jsnrice is a collector who finds trilobites interesting, has purchased a few specimens, and might not have been aware that most of the North American species formerly included in Phacops (and still called that by many commercial dealers and older collectors) is now called Eldgredgeops.  I wanted to give them a heads-up before they arranged a trade or purchase, and then were disappointed when their new specimen was not different from what they already had.  It is possible that they really wanted material of two extremely similar genera (almost indistinguishable to most collectors), in which case I apologize.

 

Don

[TyrannosaurusRex]

11 hours ago, FossilDAWG said:

Perhaps you are not aware that Eldredgeops is a new name for what used to be called Phacops?

 

Don

I was not aware. That's why I didn't address that in my LOL. My post says Eurypterus in the link rather than anything about trilobites.

 

Cheers!

[TyrannosaurusRex]

2 hours ago, FossilDAWG said:

That is true and I am aware of the taxonomic basis for dividing up Phacops and the need to erect new genera.  I will admit that when jsnrice said they already had Phacops I assumed they were talking about having a specimen of one of the common North American Hamilton Group trilobites.  It seems to me that if they are looking for an Eldredgeops and say they already have a Phacops, and they are aware of the extremely close nature of the two genera, they would have indicated that.  Someone would have to really be into trilobite taxonomy to intentionally go looking for comparative material of the two genera.  Someone with that level of sophistication would probably also be aware that the Wheeler Shale trilobite commonly sold as Peronopsis interstricta has been reassigned to Itagnostus interstrictus, and they would not have misspelled Peronopsis.  Again I am making an assumption, based on the fact that actual Peronopsis is vastly more difficult to obtain from commercial sources compared to Itagnostus interstrictus, and it is also not easy to collect personally in North America, as only P. amplaxus from the House Range and a few species from the Manuels Brook/Avalon Peninsula area of Newfoundland are retained in the genus.  Pernonopsis amplaxus is not common, and the Manuals Brook site has been closed to collecting form many years.  Also, a sophisticated trilobite collector would know that the "kingi" in Elrathia kingi should never be capitalized.  All these issues (using Phacops for Eldredgeops, "Perenopsis" (misspelled) for Itagnostus, capitalizing "kingi") are very common mistakes made by commercial fossil dealers, so I assumed that jsnrice either purchased their specimens, or IDed them based on fossil dealer web sites.

 

So, I assumed that jsnrice is a collector who finds trilobites interesting, has purchased a few specimens, and might not have been aware that most of the North American species formerly included in Phacops (and still called that by many commercial dealers and older collectors) is now called Eldgredgeops.  I wanted to give them a heads-up before they arranged a trade or purchase, and then were disappointed when their new specimen was not different from what they already had.  It is possible that they really wanted material of two extremely similar genera (almost indistinguishable to most collectors), in which case I apologize.

 

Don

I have to say that is very kind about you being concerned that they may not be aware that those trilos are not any different than what they might have. I wasn't aware of the name change. 

[doushantuo]

 

a quote from the Hildenbrand thesis:

His English could be better,but i guess the gist of it comes across

 

Peronopsis Hawle and Corda, 1847, includes the oldest described and figured
agnostoids with containing many genera of the middle Cambrian (Laurie, 1990; Naimark,
2012). More than 100 species have been assigned to this genus (Rushton, 1979; Robison, 1994,
1995; Weidner and Nielsen, 2014). The morphological characters vary during ontogeny and
within population, which leds to a complex taxonomic subdivison of Peronopsis (Robison,
1982; Naimark, 2012).
Because of these conditions there are frequent discussions about synonyms.
Acadagnostus Kobayashi, 1939, is one of the consistently discussed synonyms (e.g. Rushton,
1979; Laurie, 1990; Robison, 1994, 1995; Whittington et al., 1997). Originally the genus was
described by Kobayashi (1939) as having a pygidial lanceolate axis and a pygidial median
postaxial furrow and lacking a pair of pygidial posterolateral spines. By contrast, Peronopsis
is very variable in the pygidial median postaxial furrow as well as the occurrence of spines.
Whittington et al. (1997) presented a diagnosis of Acadagnostus which indicates pygidial
spines and the pygidial axis never reaching the border furrow. Because of the absence of a
description or discussion about the retype of the diagnosis, it is here suggested to follow
the original description of the genus, so Acadagnostus is here not considered a synonym of

Peronopis

[FossilDAWG]

I will admit that I find agnostids quite difficult to identify, even to genus in many cases.  I have several from the Conasauga Formation in Alabama that are giving me a headache.  Often you have to have perfectly preserved uncompressed specimens with the shell to have any confidence.  Compressed specimens in shale, and molds/casts without shell, often look quite different.  Also many times older genera and species were actually based on a series of specimens that were assumed to all be the same but are now considered to represent multiple species, so the older descriptions may be too broad.

 

Don 

[Raggedy Man]

5 hours ago, TyrannosaurusRex said:

I have to say that is very kind about you being concerned that they may not be aware that those trilos are not any different than what they might have. I wasn't aware of the name change. 

Here's the post from June 2014 outlining the differences and when the change were made. It's a pinned topic in the general discussion tab.

 

Paul

[ReeseF]

On 10/15/2016 at 2:43 PM, TyrannosaurusRex said:

Unfortunately, as i am sure you know, those fossils run well into the hundreds and even thousands. And there is a pretty high demand for them.

I've seen them for sale for over 2 thousand dollars. 

 

If on the other hand, you wanted to go find one yourself, New York is only a 5 hrs drive from DC.

 

This may be of some use.

http://www.fossilmuseum.net/fossils/Chelicerata/Eurypterus-remipes/Eurypterus.htm

 

You can find Eurypterids more affordable if you don't mind imperfect pieces (there are a few eBay sellers that offer 'seconds' for <$100).
Unfortunately, collecting them personally is not all that viable; you can spend a long time without any luck, and one of the commercial quarries is very expensive ($500 + a set price per piece). 

 

Eldgredgeops, on the other hand, is much more accessible