Favorite Trilobites In Your Collection!

[Trilobitologist]

The article referenced on the net is indeed me. Brett and Rudkin, 1997 was a fieldtrip guidebook I co-wrote for the 3rd International Trilobite Conference. In it we mentioned all possible known trilobites occuring in the Ordovician of southern Ontario.

And Bill mentions Physemataspis pernododusus in his book as well. The cranidium and pygidium figured are from the bottom of the Colbourne Quarry. Now completely closed to collecting.

They are extremely rare and I have never found one complete. But that's the case with many tilobites! After seeing that Dolichoharpes from Wisconsian, I need to find one from Ontario! That sure is a sweet bug!

And yup - that was a real OMG!

Thanks for your kind praise (and plugs). If you have anything you need prepared, send it along to me - that way I can get some more plugs!

[Caleb]

On the topic of Physemataspis, here is one from the Decorah Formation of Eastern Minnesota. It is truly an alien looking bug.

[piranha]

The article referenced on the net is indeed me. Brett and Rudkin, 1997 was a fieldtrip guidebook I co-wrote for the 3rd International Trilobite Conference. In it we mentioned all possible known trilobites occuring in the Ordovician of southern Ontario.

And Bill mentions Physemataspis pernododusus in his book as well. The cranidium and pygidium figured are from the bottom of the Colbourne Quarry. Now completely closed to collecting.

They are extremely rare and I have never found one complete. But that's the case with many tilobites! After seeing that Dolichoharpes from Wisconsian, I need to find one from Ontario! That sure is a sweet bug!

And yup - that was a real OMG!

Thanks for your kind praise (and plugs). If you have anything you need prepared, send it along to me - that way I can get some more plugs!

Well how about that for a terrific twist of fate?

Seriously Kevin, when I discovered the front page at "Trilobites of Eastern North America" and saw Carlton Brett's name staring back at me I automatically assumed the inverse in this case. Anyway it's great to come full circle yet again .... the irony is fantastic! Btw, there was indeed one complete individual Physemataspis in the collection of a prominent Canadian collector. I'll share the details with you via PM.

Caleb to the rescue with a Phenomenal Physemataspis from Minnesota, I love it!

Is the cephalic margin preserved and if so is it possible to see a photo please?

[Trilobitologist]

Wow Caleb! That's a truly interesting bug! I didn't think Physemetaspis had two swollen lobes like that at the front of the cephalon. It's a joy to see these rare trilobites coming out of the woodwork! Is that a described species?

It's an easy assumption to make since Carlton Brett has probably written 100 times as many articles as me. Wow is that guy productive! Although he is not a trilobite guy per se, he did co-author the Trilobites of New York Book along with Gerry and Tom. I suspect he did most of the stratigraphy and taphonomy, while Tom and Gerry (isn't that cute....) were the trilo guys.... Tom's photography is just amazing! Even have a few of my trilobites in their book as well....

[Caleb]

Wow Caleb! That's a truly interesting bug! I didn't think Physemetaspis had two swollen lobes like that at the front of the cephalon. It's a joy to see these rare trilobites coming out of the woodwork! Is that a described species?

On my website we have it listed as Physemataspis aff. coopi Evitt & Tripp, 1977, but as far as I know (and my knowledge is limited) it has not yet been described.

[Wrangellian]

Correct, as far as I know all of the trilobites from the Tanglefoot Creek site are Upper Cambrian (Steptoean). There are also some younger (Ordovician) trilobites in the area, but I have not seen the literature that narrows down their age. As I mentioned before, not much work has been done on the McKay Group.

I think it was just the abstract to the paper by Ludvigsen and Chatterton that I saw, and the title gave the age: "Upper Steptoean (Upper Cambrian) Trilobites from the McKay Group of Southeastern B.C." - Here is the quote I took from it that seems to describe the Radium site: "Unit H consists of about 1000m of recessive green and grey-green phyllite in which the primary textures have been obliterated by slaty cleavage." This sounds exactly like the Radium (Whiteswan Lake) material, not the Tanglefoot material now that I think about it..

In 1938, Kobayashi published work on Upper Cambrian trilobites of the McKay Group and following the Second World War (1955) he published on the Ordovician material. Another two papers resulted from research carried out, at the University of Alberta, on McKay Group trilobites in 1994 and 1998. Brian Chatterton's new work will bring the total to five when it is published. I'm very excited about the new work being done by Brian Chatterton and Chris Jenkins! Chatterton's new paper tops the list of my must have trilobite references!!

I have not seen any reference to Housia coming from Unit H, but would be interested in knowing where you saw this label or where the specimen was acquired from.

I bought mine from a guy in Kimberley who collected them himself and told me where the site was, and it was either him or a seller on ebay that was selling some of the same stuff (I recognized it), that called the bugs 'Housia'. There was another genus from there too, but I dont remember what it was and dont have any examples of it.

[piranha]

I bought mine from a guy in Kimberley who collected them himself and told me where the site was, and it was either him or a seller on ebay that was selling some of the same stuff (I recognized it), that called the bugs 'Housia'. There was another genus from there too, but I dont remember what it was and dont have any examples of it.

Hey Eric,

I'm pretty sure I know who you're referring to here. At least he must have been associated at some point anyway. That seller and a few of his friends had the bulk of them at ebay and elsewhere. Keep calling it Housia canadensis as that is the correct name as evidenced by the distinctive and pronounced macropleurae near the pygidium. When those first became available in bulk about 10 years ago they were offered as "undescribed" trilobites. I was quick to point out however that the example figured from Index Fossils of North America (attached) clearly indicates these as Housia canadensis, Walcott 1916.

Hey ... even a blind worm catches a worm once in a while!

Housia canadensis - 1" (25mm)

Upper Cambrian - McKay Group

Radium, British Columbia, Canada

[palaeopix]

I think it was just the abstract to the paper by Ludvigsen and Chatterton that I saw, and the title gave the age: "Upper Steptoean (Upper Cambrian) Trilobites from the McKay Group of Southeastern B.C." - Here is the quote I took from it that seems to describe the Radium site: "Unit H consists of about 1000m of recessive green and grey-green phyllite in which the primary textures have been obliterated by slaty cleavage." This sounds exactly like the Radium (Whiteswan Lake) material, not the Tanglefoot material now that I think about it..

The trilobites from Tanglefoot Creek are found in the lower half of Unit H according to Chatterton and Ludvigsen (1998). The Unit H designation for the Tanglefoot Creek area is puzzling and appears to be an incomplete description of the lithology found at the site. Chatterton and Ludvigsen's (1998) paper only mentions the following trilobites from the Tanglefoot Creek Locality: Homagnostus sp., Pseudagnostus communis, Agnostotes clavata, Wujiajiania sutherlandi, Aciculolenus palmeri, Labiostria westropi, Burnetiella leechi, Elvinia roemeri, Irvingella major, Irvingella sp. A, Hedinaspis canadensis, Pterocephalia norfordi and Cliffia c.f. latagenae. The paper makes no reference to Housia or any of the other genera from the Whiteswan Lake area.

I expect the new work by Chatterton will discuss Housia and the other 15+ new species from the Whiteswan and additional Tanglefoot Creek sites. I agree that the specimens of Housia appear to be preserved in the diagnostic green phyllites of Unit H, but I have not yet seen this confirmed in the literature! Here is a preliminary list of trilobites from these areas (courtesy of the Western Trilobite Association): Note that the underlined names lead to photos of those specimens. I also agree with Scott that Housia canadensis is the name you should be using for your specimen, however I have seen another species of Housia as well somewhere on the internet. I've also seen specimens called Aphelaspis sp. on eBay from the Whiteswan Lake site.

?Dicanthopyge

Elvinia sp. aff. E. roemeri [Quarry Site 4]

Housia sp.

Irvingella species A [Quarry Site 1]

"Jensonia"?

Labiostria n. sp. [Quarry Site 1]

Orygmaspis contracta

Orygmaspis new species (similar to O. contracta, but less pygidial border spines) [This is most likely conspecific with O. Type 2

Orgmaspis Type 2 (similar to O. contracta, but less pygidial border spines) [Quarry Site 1]

Orgmaspis Type 3 (long curved genal spines, 2 very long macropleural spines on thorax, no pygidial border spines) [Quarry Site 1]

Pterocephalia - undescribed new species

Tricrepicephalus sp.

"Widespinia"

Wujiajiania sutherlandi Chatterton & Ludvigsen, 1998

new genus? new species (with anomalous tailspine) [site 4]

new genus? new species (with long genal spines) [Quarry Site 4]

Edited February 8, 2011 by palaeopix

[Wrangellian]

Well I'm still puzzled, if Unit H is the greenish phyllite, and the Tanglefoot material does not fit that description, but is also Unit H. I can't wait for someone to sort it all out.. hope I'll hear about it (from you guys or otherwise) if there is a new paper out.

[Triloman]

Well Done RC...I raise Triarthrus in 4 different poses: Ventral, Dorsal, Lateral and Rolled!

cheers,

PzF

Ventral: 3.5 cm

2 dorsal with perfect antennae 1.1 and 1.3 cm

Lateral 2.4 cm

Rolled 1 cm

WOW!!! Seen similar pictures like this in fossil books but these are unbeleivable

[Terry Dactyll]

Some great bugs guys.... Very nice to see some 'Quality stuff'

[Trilobitologist]

Thanks for the plug for the WTA ( http://www.westernta.com/WTA.htm ). It took me a long time to put together all the research and photos for that site. Of course the lists of Formations are far from complete, I tried to include most of the more common trilobite-rich formations in the western US and a few from western Canada. The species lists also are a guide only, as I put these together from the literature known at the time as well as any new information gleened from collectors or recent work. Of course, I must also thank all of the collectors and academics who assisted me in sending photos and information!

Glad you enjoy the page. It was designed to help as a first guide to trilobite collectors in identifying their specimens from western N.A.

Cheers!

[ems]

Another infamous homalonotid is the "ELVIS" bug AKA Burmeisteria,

Burmeisterella, etc., but is actually assigned as Scabrella propradoana.

Elvis bugs are usually fabricated molds. This is a ultra rare 'real' example.

Hey piranha!

Did you count the thoracal segments? Adult specimens of Scabrella always have 13!!!

Here is my Scabrella propradoana(MÜLLER 2005)

Edited February 9, 2011 by ems

[piranha]

On 2/9/2011 at 4:51 AM, ems said:

Hey piranha!

Did you count the thoracal segments? Adult specimens of Scabrella always have 13!!!

Here is my Scabrella propradoana(MÜLLER 2005)

Hey EMS!

All accounted for when I acquired it about 15 years ago ... still 11 thoracic tergites on mine! 

I just went looking for that paper. I changed computers recently and the file is missing. Do you have a copy? Mine is a sub-adult of course measuring 8.5" (22cm). Although you didn't mention it, I imagine yours must be around the 12 inch mark representing approximately max size for these beastly bugs. Yours is quite nice as well and only one of a handful I've ever seen that are actually legitimate. I was rather fortunate to get this one as I've never seen another juvenile specimen all these years.

[piranha]

As I puzzle over my juvenile Trimerus however, there seems to be no trouble at all with 13 segments.

I'll have to hope for bizarre pathology in this instance lest the dreaded missing segments strike again!

[piranha]

The plot thickens. 

A quick refresher from the treatise on the Family Calymenidae suggests a thoracic count of 11, 12 or 13 segments is possible.

Calling all TFF Trilobitologists (Kevin) to help us illuminate all of the possible hypotheses advanced in this discussion please.

[piranha]

Kevin .... before I'm to be pilloried here .... 

Homalonotidae (close to Calymenidae) calls for 13.

The argument for segment reduction appears flawed?

Dimorphism or pathology to the rescue PLEASE! 

[Quarryrat]

My recent favourite bug...from a well known MINERAL quarry in Dundas,Ontario..I suspected there might be fossils in the lowest areas (exposing the upper Eramosa fm.). They said there were no good fossils there...they said it couldn't be done...heh,heh...love to prove 'em wrong!!

[Trilobitologist]

Don't ask for me to come to the rescue. I will only throw monkey wrenches into the works.....

First of all, I don't want to disappoint anybody.........but are you really really sure that your Scabrellas or Burmeisterellas (or whatever you wish to call the Elvis-type bugs - there are several by the way....) are truly real?

I don't say this without experience or to be mean ....... It looks like the exoskeleton on the Scabrella you figured could be 100% complete.

What I mean is the Scabrella figured seems to be a composite. At least to me (from the photos) the cephalon seems to be composited. Don't get me wrong - these Moroccans (or whoever) are tricky. I would need to check the specimen out for myself (which includes various analyses as well as completely going over it with an airdent under magnification). Believe me - I could tell after working on it myself. So could Gerry or Zarko or Scott - or one of the other top notch guys. Have your bugs looked at and worked on and that way it could be documented for sure. Some of the best Museums in the world are fooled by these composites.

That said - it still could be 100% real. And Scott - yours could be a composite (or telescoped).

And I believe that segment number in homalonotid species is fairly consistent. And calymenid species in general. If there are a different number of segments within a species, I would be as little suspicious. Doesn't mean it couldn't happen, but because of the Moroccan forgeries, nothing is for certain.

To answer your question about where segments are released from - it is from the pygidium.

To answer the questions about sexual dimorphism - no cases as far as I know have been shown for number of thoracic segments. Numbers of segments normally have to do with ontogeny and perhaps heterochrony of some sort - not sexual dimorphism. Sexual dimorphism usually shows other characters such as spines and spine length, number of eye facets (although I don't go for this one), and size ratios of different species within the same formation. I am certainly only simplifying things here, but it is a whole nuther' can o' worms.......

Controversy anyone......???

[piranha]

Thanks Kevin, very useful information here. The Trilobitologist always comes to the rescue!! 

Real? YES SIR ... Absolutely 100% certain of that. Countless hours have been spent studying it and I've seen the scores of fakes over the years, no mistaking the real deal in this instance. There's a small strip on the left anterior cephalic margin and another at the left margin of the pygidium that have been restored. I calculate 2-3% resto of the bug in its entirety, and in any event, fully disclosed to me before I coughed up a lung to acquire it. It's back on page 2 of this thread for anyone wishing to give it another once over. All of the fine pitted integument of the cephalon is strikingly reminiscent of a New York Dipleura or Trimerus and the knobby ornamentation of the pygidium is comprised of a wonderful mineralized chitinous preservation as well.

I'll have to display it next to my seven segmented Isotelus as part of my new Trilobite Freak Show!! 

[piranha]

To answer your question about where segments are released from - it is from the pygidium.

Hey Kevin,

Could you elaborate on this point please? I'm taking the lead here from Sam Gon's page on ontogeny with Shumardia referenced as the classic example. Paraphrasing his explanation; for trilobites with similar thoracic segments, it's difficult to know whether they release from the cephalon backward or pygidium forward and remains unclear and unknown? Shumardia, on the other hand, with its long-spined segment as a marker in ontogenetic study, clearly indicates the forward release from the pygidium. It's worth mentioning the last update there was November 2007. What are the most recent developments regarding trilobite ontogeny that informs that conclusion for all?

LINK

[ems]

@ piranha: I will send you the paper next time I will have access to my copy. May be tomorrow.

@ trilobitologist: I also took into consideration that the cephalon of my specimen might be added in some way, as the matrix is not exactly identical. The specimen might originally have been a salter. It might have been prepped in that way that the cepahlon has been flipped around and has been fixed onto the thoracopygon. If so, everything fits together, at least

Cheers

Edited February 10, 2011 by ems

[Trilobitologist]

Scott - New trilobite Treatise (1997) pg. 194

It's one fairly definitive reference . I believe that most recent studies have shown that meraspid transitory pgygidia actually contain the protothoracic segments that will be released. So - in answer - I would say released from the pygidium.

EMS - yes it could be. Doesn't mean the trilobite is not 100% complete (in terms of all the parts of the exoskeleton). It's just composited.

Scott - same thing. I don't doubt that the trilobite is 97 to 100% complete. The thing is that I have seen very clever composites. I have actually seen unprepared thoracopygia in the field, as well as complete cephalons with cheeks. But I have never seen an unprepared specimen with all these parts. The large Scabrellas are actually encountered often (especially in the "Psychopyge couche" that rims the entire Mountain of Issoumour, as well as the Pass at Bou Dib, etc.). It's the most noticeable layer that you can see, even from a distance of many kilometers. It is an impressive digging effort!

The thing I would look for the most is the attachment between the head and the thorax, as well as all of the matrix just under the trilobite. If the head is composited on, there will be evidence after airdenting between the specimen and the matrix.

If it is 100% complete and real - Congratulations! There are so few out there. It is like an Acanthopyge 100% complete with cheeks. I have yet to see an actual 100% proven specimen in person! Seen lots on the internet though....

EMS - if you have a pdf of the article, could you PM me as well? I have a paper copy, but not the pdf.

Oh - and I don't always come to the rescue! Unless you are a maiden in distress.... But seriously - don't take my word for everything - I love to generate controversy.

Anyhow - this forum thread is awesome! but I think the others following this thread will get bored with us because they want to see more amazing bugs from your collections........

Cheers!

[Trilobitologist]

What I want to see is a 9 segment Isotelus. Seen quite a few 7s, but asaphids often have the head telescoped over the first segment(s). You need to begin a new thread - Trilobite Freakshow. Maybe we'll see what interesting things come out of the woodwork. I want to see a trilobite at the end of it's crawling trace.........

Anyhow, we can all marvel at these freaks and say "I don't believe it" Let's call it Ripley's Trilobites.....

Trilobites having gender, trilobite injuries, trilobites in burrows, trilobites with epibionts, trilobites crawling out of their moult (I wish), anything trilobitologically taphonomical.......

[piranha]

Mine was prepared here in the states by Mike Thomas, the son of legendary Gene Thomas. It was prepared from a cross-section and not flipped or composited. Let's do a quick Paleo-CSI on the big fella for fun. I've attached a large image file of the cephalon for scrutiny. Here's the clincher ... check at the median point of the occipital ring. There you should see a line of crazing in the exoskeleton infilled with matrix. Now follow that back as the crazing traverses the segments. There are clever deceptions in the fossil racket, but let's face it, some evidence cannot be faked. Furthermore, I've lined up every last millimeter on all of my trilobites. I can tell you of even a match-head sized spot of restore on any of my fossils. And just because of a fossil's storied provenance and assurances I double check everything to be certain. Too many cornball cliches to quote; check twice, safe than sorry, born at night but not last night, and so on.

Back to the so-called boring stuff for a moment. I was really hoping for more than that Kevin. I read both treatise sections on ontogeny again for the umpteenth time. My take away is quite nebulous and vague on this point. I remain unconvinced unfortunately. Although instead of counting enrolled phacops to fall asleep last night I substituted phacopid instars in their place!

OK if you insist, maybe we should get back to PzF's Big Top Show of Trilobites.

As you like to say .... you're a GEEK Kevin!

Can I be the GIT?