Trying to ID two extant taxidermy rays with a caudal sting

[MarcoSr]

This post contains a lot of information about extant rays that I learned from “Last, White, de Carvalho, Seret, Stehmann, Naylor 2016 Rays of the World” that I hope TFF readers will find both interesting and informative.

 

Below is a male and female ray, each with a caudal sting (I’m using that terminology because that is the terminology used in “Last, White, de Carvalho, Seret, Stehmann, Naylor 2016 Rays of the World” that I draw on heavily for this post), that I purchased on e-bay.  When I saw the rays with the caudal stings, I thought that they were stingrays from the family Dasyatidae and maybe from the genus Dasyatis.  I bought them because I thought it would be neat to do a post on them because we see so many fossil caudal stings and teeth that get identified as stingray (Dasyatidae or even Dasyatis).  However when I pulled out “Last, White, de Carvalho, Seret, Stehmann, Naylor 2016 Rays of the World” to id them I was really surprised at how many ray families have species with caudal stings.  Besides the family Dasyatidae (stingrays), there were the families Hexatrygonidae (Sixgill Stingrays), Gymnuridae (Butterfly Rays),  Potamotrygonidae (Neotropical Stingrays), Urotrygonidae (Round Rays), Plesiobatidae (Giant Stingarees),Urolophidae (Stingarees), Myliobatidae (Eagle Rays), Aetobatidae (Pelagic Eagle Rays), Rhinopteridae (Cownose Rays) and Mobulidae (Devilrays).  I looked at hundreds of ray pictures in Last 2016 of rays with caudal stings and soon realized that a ray’s tail features can really help you to narrow down the possible families that the ray can be from.  So the caudal sting eliminated a number of families that don’t have caudal stings and the tail features of these online rays eliminated a number of other families/genera.  Once I got to the possible families/genera with tail features that might match I used detailed identification for each ray to get to a genus and then to a species id.  At this point I looked at color (note color on a taxidermy ray can change both from the chemicals used in the taxidermy and from aging), dimensioning like ray disc length and width (Note the disc curling in the online specimens made taking accurate measurements difficult so I used string to try to compensate)  and tail length, ray max size, features of the eyes, spiracles, nostrils, nasal curtain, snout, disc shape (again the disc curling made this very difficult to see), placoid scales (Last 2016 uses the terminology denticles) and thorns, etc.

 

Here are the two e-bay rays so you can see their general features and the general features of the tails. (Note I believe that both tails have caudal fins and I believe the male tail may have a dorsal fold):

 

Male ray dorsal view:

 

 

 

Male ray tail end:

 

 

 

Female ray dorsal view:

 

 

 

Female ray tail end:

 

 

 

In the following discussion, I will show representative ray pictures (all from “Last, White, de Carvalho, Seret, Stehmann, Naylor 2016 Rays of the World”) from the different ray families with stings to illustrate the tails.

 

Gymnuridae (Butterfly Rays) – 1 genus/10 species – In this family you have species with no caudal stings, poorly developed caudal stings, and strong and well developed caudal stings.  The tails are short and slender. Last 2016

 

Here is a Gymnura altavela (Spiny Butterfly Ray) picture Last 2016:

 

 

 

I eliminated this family not only by the tail features but also by the distinct lozenge shaped disc.

 

Myliobatidae (Eagle Rays) – 2 genera/18 species – Aetomylaeus two of seven species have caudal stings (1 or 2); Myliobatis all eleven species have caudal stings (from 1 to 3 depending on the species).  The tail is much longer than the disc, filamentous distally, and lacks a caudal fin. Last 2016

 

Here is a Myliobatis californicus (Bat Eagle Ray) picture Last 2016:

 

 

 

Aetobatidae (Pelagic Eagle Rays) – 1 genus/5 species – All species have caudal stings (usually 1 or 2, A. ocellatus rarely up to 5).  The tails are elongate and whip-like. Last 2016

 

Here is an Aetobatus narinari (Whitespotted Eagle Ray) picture Last 2016:

 

 

 

Rhinopteridae (Cownose Rays) – 1 genus/8 species – Caudal stings are present for all species but often detached.  The tail is normally longer than the disc (Tail length varies among the species) and is filamentous distally and lacks a caudal fin. Last 2016

 

Here is a Rhinoptera bonasus (American Cownose Ray) picture Last 2016:

 

 

 

I easily eliminated the three previous families not only on the tail features but also on a number of other features like the teeth (In all previous three families the species all have plate-like teeth).

 

Mobulidae (Devilrays) – 1 genus/ 8 species – Six species are without caudal stings.  M. birostris has a reduced caudal spine encased in a calcified lump.  M. mobular has a short serrated caudal spine. The tail is whip-like and varies from long to relatively short, usually much less than the width of the disc. Last 2016

 

Here is a Mobula mobular (Giant Devilray) picture Last 2016:

 

 

 

I easily eliminated this family for a lot of different features including the tail and the prominent cephalic lobes.

 

Potamotrygonidae (Neotropical Stingrays) – 1 marine genus, 4 freshwater genera/34 valid species (Several new freshwater species being currently described).  All species have caudal stings (some species have 2 caudal stings) which range from very robust to slender and small to vestigial.   Tails range from short, very stout and muscular to extremely long and whip-like. Last 2016

 

Because of the tail variation I show pictures of three species below.

 

Here is a Paratrygon aiereba (Discus Stingray) picture Last 2016:

 

 

 

Here is a Potamotrygon amandae (Amanda's Freshwater Stingray) picture Last 2016:

 

 

 

Here is a Styracura schmardae (Atlantic chupare) picture Last 2016:

 

 

 

I eliminated this family on the basis of the tails.

 

Dasyatidae (Stingrays) – 19 genera/86 species (the two largest genera Dasyatis and Himantura each consist of several genera which require taxonomic changes).  Most species have 1 or more serrated caudal stings.  The tails, typically longer than the disc and lacking dorsal, anal and caudal fins, vary and can be greatly extended and whip-like.  Last 2016

 

Because of the tail variation I will show pictures of 6 species.

 

Here is a Dasyatis pastinaca (Common Stingray) picture Last 2016:

 

 

 

Here is a Maculabatis pastinacoides (Round Whipray) picture Last 2016:

 

 

 

Here is a Neotrygon annotata (Plain Maskray) picture Last 2016:

 

 

 

I eliminated the whiprays, maskrays and most of the stingrays based upon the tails.  I had to look closer at the cowtail, fantail, and a couple of stingrays below.

 

Here is a Pastinachus ater (Broad Cowtail Ray) picture Last 2016:

 

 

 

Here is a Taeniura lymma (Bluespotted Fantail Ray) Last 2016:

 

 

 

Here is a Taeniurops meyeni (Blotched Stingray) picture Last 2016:

 

 

 

I eliminated the cowtail rays because their tails end in a short flexible filament.  Both the genus Taeniura and the genus Taeniurops have two species only.  The fantail rays have large vivid blue spots.  I eliminated them based upon the spots and the tail features.  I eliminated Taeniurops grabatus based upon the tail and other features like color and the presence of low thornlets dispersed centrally over the upper disc and tail which the online specimens don’t have.  Taeniurops meyeri is a very large ray with newborns having a 30-35 cm disc width which is quite a bit bigger than the e-bay specimens. Last 2016

 

The next four families Hexatrygonidae (Sixgill Stingrays),  Plesiobatidae (Giant Stingarees), Urolophidae (Stingarees), and Urotrygonidae (Round Rays) all have well-developed caudal fins at the end of the tail consisting of  long-based upper and lower lobes Last 2016 like the e-bay specimens.

 

Hexatrygonidae (Sixgill Stingrays) – 1 genus/ 1 species.  Species has 1 or 2 caudal stings.  The tail is slender but not whip-like with a well-developed caudal fin which is elongate, with upper and lower lobes narrow and similar in length. Last 2016

 

Here is a Hexatrygon bikelli (Sixgill Stingray) picture Last 2016:

 

 

 

The tail with a well-developed caudal fin on this species is definitely similar to the female e-bay ray tail.  However it was easy to eliminate this species based upon other features like the six gill slits, long rostrum, newborn size larger than online specimen size, very small pelvic fins etc. Last 2016

 

Plesiobatidae (Giant Stingarees) – 1 genus/1 species.  The species usually has a strong caudal sting.  Tail is narrow based and slender but not whip-like with a caudal fin, half the length of the tail, which is elongate and slender at the base. Last 2016

 

Here is a Plesiobatis daviesi (Giant Stingaree) picture Last 2016:

 

 

 

The tail with a well-developed caudal fin on this species is definitely similar to the female e-bay ray tail.  However it was easy to eliminate this species based upon other features the long rostrum, newborn size larger than online specimen size, upper disc and tail densely covered with small placoid scales (denticles), etc. Last 2016

 

Urolophidae (Stingarees) – 3 genera/28 species.  Species have 1 or more serrated caudal stings.  The tail is short and slender with an elongate lobe-like caudal fin and may have a narrow cutaneous skin fold along each side, but lacks an anal fin and skin folds on the dorsal and ventral mid-lines. Last 2016

 

Here is an Urolophus aurantiacus (Oriental Stingaree) picture Last 2016:

 

 

 

Based upon the tail features and a long list of other features I believe the male e-bay ray is Urolophus aurantiacus (Oriental Stingaree).

 

Urotrygonidae (Round Rays) – 2 genera/16 species.  Species normally have a caudal sting preceding the caudal fin.  The tail is relatively broad based, usually shorter than the disc, and lacks dorsal and anal fins.  The tail has a well-developed caudal fin, consisting of short dorsal and longer ventral lobes,  which varies from rather short to very elongate.  Last 2016

 

Here is an Urotrygon microphthalmum (Smalleye Round Ray) picture Last 2016:

 

 

 

Based upon the tail features and a long list of other features I believe the female e-bay ray is Urotrygon microphthalmum (Smalleye Round Ray).

 

Continued in next reply

 

Marco Sr.

[MarcoSr]

Here are the two rays:

 

Male ray which I believe is Urolophus aurantiacus (Oriental Stingaree) with a picture and Identification from “Last, White, de Carvalho, Seret, Stehmann, Naylor 2016 Rays of the World”:

 

 

 

 

I went through the identification features that I could fully understand and the male specimen seemed to match everything like color, eyes, spiracles, disc, tail, caudal fin, lack of thorns and placoid scales (denticles), nasal flap, teeth etc.  However it was hard to visualize the overall disc shape with all of the curling.  It was also difficult to take measurements with the curling of the disc and twisting of the tail.  I used string to try to follow the curls and twists.  It was also difficult to determine the end point of the disc and where exactly the tail began.  So as I measured the disc and the tail, the tail is not 72% to 84% of disc length but more like 90%. But I could have easily not measured this exactly with the mentioned difficulties. Also there may be a feature or features that don’t match that might be very obvious to a ray expert which I’m not.

 

Dorsal and ventral views (disc 6.125 inches long by 6.5 inches wide, tail 5.5 inches long, total length 11.5 inches):

 

 

 

 

Claspers (1.75 & 1.625 inches):

 

 

 

Caudal sting (1.625 inches) dorsal view:

 

 

 

Tail caudal fin:

 

 

 

Ventral view of oronasal region and tooth band (mouth 13 mm):

 

 

 

Tooth band close-up:

 

 

 

I looked at the entire ray with both a 10 X loupe and with my microscope and did not see any placoid scales (denticles), thorns or tubercles.

 

Skin between eyes dorsal view:

 

 

 

Skin close-up back of head dorsal view:

 

 

 

Skin base of tail dorsal view:

 

 

 

Skin center of disc ventral view:

 

 

 

Continued in next reply

 

Marco Sr.

[MarcoSr]

Female ray which I believe is Urotrygon microphthalmum (Smalleye Round Ray) with a picture and Identification from “Last, White, de Carvalho, Seret, Stehmann, Naylor 2016 Rays of the World”:

 

 

 

 

I have some serious doubts about this ID.  I went through the identification features that I could fully understand and the female specimen seemed to match everything like color, eyes, spiracles, disc, tail, caudal fin, lack of thorns, having scattered placoid scales (denticles), nasal flap, teeth etc.  However it was hard to visualize the overall disc shape and pelvic fin shape with all of the curling.  It was also difficult to take measurements with the curling of the disc and twisting of the tail.  I took the measurements multiple times using string to try to follow the curls and twists and measured a slightly different amount almost each time.  It was also difficult to determine the end point of the disc and where exactly the tail began.  So as I measured the disc and the tail, the tail is not 56% to 59% of total length but more like 54%. But I could have easily not measured this exactly with the mentioned difficulties. The bigger concern is that this ray is slightly bigger than the maximum size listed by Last 2016, with disc width at 15.24 cm versus 13.5 cm and total length at 30.8 cm versus 30 cm.  There were a number of other round ray species that were possibilities but there were bigger size discrepancies or there were other features that clearly didn’t match like thorns and thorn patterns which eliminated them.   I also eliminated species of other genera that were possibilities for the same reasons.  Also there may be a feature or features that don’t match that might be very obvious to a ray expert which I’m not.  It was a little disappointing going through all of this and not coming to a more certain ID.

 

 

Dorsal and ventral views (disc 6 inches long by 6 wide inches, tail 6.5 inches long, total length 12.125 inches):

 

 

 

 

Caudal sting (1.75 inches) dorsal view:

 

 

 

Tail caudal fin:

 

 

 

Ventral view of oronasal region and tooth band (mouth 20 mm):

 

 

 

Tooth band close-up:

 

 

 

I looked at the entire ray with both a 10 X loupe and with my microscope and did not see any thorns.  However I did see widely scattered placoid scales (denticles) on the dorsal side of the disc and several small areas where placoid scales seemed to be piled up (probably the result of the taxidermy procedure).

 

Skin between eyes dorsal view:

 

 

 

Skin base of tail dorsal view:

 

 

 

Skin close-up base of tail dorsal view:

 

 

 

Skin right side of disc ventral view:

 

 

 

Placoid scales (denticles) close-up dorsal view (Note there were a few visible scattered placoid scales still embedded in the skin on the dorsal surface of the disc.  However there were also several patches of placoid scales that were jumbled together, as seen in the below picture, that weren't embedded in the skin.  These probably loosened up and grouped together in the taxidermy process because they are stuck to the disc surface.):

 

 

 

I’m not really sure that I got to the correct species IDs for these two online rays but I sure learned a lot about ray families with caudal stings, about ray tail features and other ray identifying features.  Without “Last, White, de Carvalho, Seret, Stehmann, Naylor 2016 Rays of the World” I would have been totally lost.  Also I hope I made TFF readers aware of how many different ray genera/species have caudal stings.

 

Marco Sr.

 

[Coco]

Marco, have you thought about the fact that the rays may have narrowed a little bit during drying ? Perhaps the measurements of fresh / alive rays aren't exactly the same once they are dried.

 

Coco

 

[MarcoSr]

1 hour ago, Coco said:

Marco, have you thought about the fact that the rays may have narrowed a little bit during drying ? Perhaps the measurements of fresh / alive rays aren't exactly the same once they are dried.

 

Coco

 

Coco

 

I definitely agree that the taxidermy and drying could change the dimensions.  However, I don't really know how much shrinking actually occurs and if the shrinking affects some dimensions more than others to change the different percentages that researchers use to ID a species.  I would definitely prefer to try to ID a freshly caught ray with natural colors and dimensions not affected by taxidermy chemicals, aging etc.

 

Marco Sr.

[Tidgy's Dad]

Fascinating process of elimination.

I didn't realize that there were so many species of ray, let alone so many with caudal stingers. 

Once again thanks for you. 

[ynot]

Very nice dissertation, again.

Thanks for sharing it.

 

[MarcoSr]

5 minutes ago, Tidgy's Dad said:

Fascinating process of elimination.

I didn't realize that there were so many species of ray, let alone so many with caudal stingers. 

Once again thanks for you. 

 

There are many more ray families that I didn't address in my post above because all of the species in the families don't have caudal stings: Pristidae (Sawfishes), Rhinidae (Wedgefishes), Rhinobatidae (Guitarfishes), Glaucostegidae (Giant Guitarfishes), Trygonorrhinidae (Banjo Rays), Platyrhinidae (Fanrays), Zanobatidae (Panrays), Narcinidae (Numbfishes), Narkidae (Sleeper Rays), Hypnidae (Coffin Rays), Torpedinidae (Torpedo Rays), Rajidae (Skates), Arhynchobatidae (Softnose Skates), Gurgesiellidae (Pygmy Skates), and Anacanthobatidae (Legskates).  When a ray has a caudal sting it eliminates a lot of families from ID consideration.

 

Marco Sr.

[Tidgy's Dad]

4 minutes ago, MarcoSr said:

 

There are many more ray families that I didn't address in my post above because all of the species in the families don't have caudal stings: Pristidae (Sawfishes), Rhinidae (Wedgefishes), Rhinobatidae (Guitarfishes), Glaucostegidae (Giant Guitarfishes), Trygonorrhinidae (Banjo Rays), Platyrhinidae (Fanrays), Zanobatidae (Panrays), Narcinidae (Numbfishes), Narkidae (Sleeper Rays), Hypnidae (Coffin Rays), Torpedinidae (Torpedo Rays), Rajidae (Skates), Arhynchobatidae (Softnose Skates), Gurgesiellidae (Pygmy Skates), and Anacanthobatidae (Legskates).  When a ray has a caudal sting it eliminates a lot of families from ID consideration.

 

Marco Sr.

Yeah, I got you'd eliminated some due to not having caudal stings, but just had no idea of the diversity and total number of species of extant rays.

What an amazing group.

[MarcoSr]

2 minutes ago, ynot said:

Very nice dissertation, again.

Thanks for sharing it.

 

 

Tony

 

I had no idea how diverse rays were until I tried to ID these e-bay rays.  The diversity makes me rethink the IDs that we typically give for fossil ray/skate micro teeth and ray caudal stings.  There are a lot more possibilities for micro ray/skate teeth than just Dasyatis and Raja and for ray caudal stings than just Dasyatis and Myliobatis or Aetobatus.

 

Marco Sr.

[ynot]

9 minutes ago, MarcoSr said:

 

Tony

 

I had no idea how diverse rays were until I tried to ID these e-bay rays.  The diversity makes me rethink the IDs that we typically give for fossil ray/skate micro teeth and ray caudal stings.  There are a lot more possibilities for micro ray/skate teeth than just Dasyatis and Raja and for ray caudal stings than just Dasyatis and Myliobatis or Aetobatus.

 

Marco Sr.

Yeah, I was thinking that too.

Would be nice to have a outline of the different tooth layouts of the different genus. (I suspect species would be a big can of worms).

[Yoda]

Really interesting.

Thanks for sharing.

 

I have a tank with a pair of Potamotrygon hystrix.

Best fish I have ever kept

[MarcoSr]

6 hours ago, Yoda said:

I have a tank with a pair of Potamotrygon hystrix.

Best fish I have ever kept

 

I looked up Potamotrygon hystrix in Last 2016.  Wow, really cool fresh water rays from South America.  Their common name is "Porcupine Freshwater Stingray".  Sounds like they are called porcupine because their disc is very prickly with numerous small denticles on it and their tail has numerous thorns, thornlets, and denticles  with a well developed caudal sting.  You definitely wouldn't want to try to grab them by the tail.  I don't know how large they can grow in your tank, but in the wild they can get to a disc width of around 40 cm (almost 16 inches), although they are commonly smaller.

 

Marco Sr.

[MarcoSr]

19 hours ago, ynot said:

Yeah, I was thinking that too.

Would be nice to have a outline of the different tooth layouts of the different genus. (I suspect species would be a big can of worms).

 

Tony

 

I bought the 790 page " Last, White, de Carvalho, Seret, Stehmann, Naylor 2016 Rays of the World” book because I was hoping it would have at least line drawings of the ray jaws, teeth, placoid scales, thorns etc.  It does have a few line drawings of jaws at the family level but nothing really at the genus level or the species level which would have been very useful.  There is a line or two in the identification of each species that talks about teeth but the description gives mostly a number of teeth (range) for the upper jaws.  However, this book has been very useful for me to help understand the different ray families and the different features used to ID extant rays to a family/genus/species.  Teeth don't really play much of a role at all in the ID process.  The actual features of dermal denticles, thorns, thornlets etc. themselves don't really play a role in the ID process but their presence or lack thereof or their location, density, pattern etc does.  It was also interesting to see DNA analysis starting to play more of a role (overriding placement based upon features alone)  in the family and genus taxonomy.

 

Marco Sr.

[Yoda]

Here is my pair.

They have grown quite a bit in the 3 years  since this photo was taken

 

 

[ynot]

8 hours ago, Yoda said:

They have grown quite a bit in the 3 years  since this photo was taken

No scale.

So how big are they, now and then?

[MarcoSr]

8 hours ago, Yoda said:

Here is my pair.

They have grown quite a bit in the 3 years  since this photo was taken

 

 

 

Wow, really nice.  I've had both freshwater and saltwater tanks but I have never kept rays.  My older son had a huge saltwater tank years back with a small ray.  That ray was pretty plain looking, not as colorful as yours.

 

Marco Sr.

[siteseer]

On 1/30/2019 at 10:49 AM, MarcoSr said:

 

Tony

 

I had no idea how diverse rays were until I tried to ID these e-bay rays.  The diversity makes me rethink the IDs that we typically give for fossil ray/skate micro teeth and ray caudal stings.  There are a lot more possibilities for micro ray/skate teeth than just Dasyatis and Raja and for ray caudal stings than just Dasyatis and Myliobatis or Aetobatus.

 

Marco Sr.

 

 

Marco Sr., 

 

Great thread.  You have a sickness that I have.  You buy specimens because you want to figure out what they are.  I've reached the point where I spend more on books and photocopying than on specimens.  In fact i don't think I bought any fossils last year though I did get a few in trade and as gifts.

 

I've been told by at least one researcher that caudal stings can't be identified to genus.

 

I hadn't heard of that book before this thread though the editors have familiar names.  Gordon Hubbell has advised me to pick up "Sharks and Rays of Australia" by Last and Stevens.  Originally published in 1994, the book was put out again as a revised edition in 2009.  Unfortunately, the price tag of Last and Stevens (2009) and Last et al (2016) is in the same ballpark (over $100).  Both sound like they are worth it.

 

Jess

[MarcoSr]

2 hours ago, siteseer said:

 

 

Marco Sr., 

 

Great thread.  You have a sickness that I have.  You buy specimens because you want to figure out what they are.  I've reached the point where I spend more on books and photocopying than on specimens.  In fact i don't think I bought any fossils last year though I did get a few in trade and as gifts.

 

I've been told by at least one researcher that caudal stings can't be identified to genus.

 

I hadn't heard of that book before this thread though the editors have familiar names.  Gordon Hubbell has advised me to pick up "Sharks and Rays of Australia" by Last and Stevens.  Originally published in 1994, the book was put out again as a revised edition in 2009.  Unfortunately, the price tag of Last and Stevens (2009) and Last et al (2016) is in the same ballpark (over $100).  Both sound like they are worth it.

 

Jess

 

Jess

 

If you want to understand the different extant ray families/genera/species, understand the terminology used to describe extant rays, see a write-up on each currently identified extant ray, and maybe ID an extant ray, Last  et al (2016) is a great book.  This book did help tremendously with the ID of the e-bay taxidermy rays.  However it doesn't address teeth much at all other than tooth counts.  Line drawings of a few teeth would have really made the book much more useful.  Also features of the caudal stings and the denticles, thorns and thornlets aren't really addressed.  The lead-ins to each family are really useful to understand the unique features of the extant rays in each family.  Below are two typical species ID pages from “Last, White, de Carvalho, Seret, Stehmann, Naylor 2016 Rays of the World” .  Each species has a single ID page like this.

 

 

 

 

 

Marco Sr.

[Plantguy]

Quite informative as always..the pics and detail within are stunning. I love to see this kind of passion and curiosity! Thanks for sharing!

Makes me want to go look at ray bits and pieces again...I need to go do chores!

Regards, Chris 

[Yoda]

21 hours ago, ynot said:

No scale.

So how big are they, now and then?

They must be about 1/3 bigger now. 

Prob disc size jusrt under 30cm

 

Female expecting her first litter of pups which I am very excited about.

 

Will take some photos over the weekend

[Coco]

Hi,

 

7 hours ago, siteseer said:

Gordon Hubbell has advised me to pick up "Sharks and Rays of Australia" by Last and Stevens.  Originally published in 1994, the book was put out again as a revised edition in 2009.  Unfortunately, the price tag of Last and Stevens (2009) and Last et al (2016) is in the same ballpark (over $100). 

I have the Last & Stevens 1994, a used publication that cost me a lot of money 8 years ago... Good book but I haven't a lot of australian jaws !

 

Coco

[MarcoSr]

4 hours ago, Plantguy said:

Quite informative as always..the pics and detail within are stunning. I love to see this kind of passion and curiosity! Thanks for sharing!

Makes me want to go look at ray bits and pieces again...I need to go do chores!

Regards, Chris 

 

Chris

 

I started looking at extant rays to better understand my ray fossils.  I'm convinced there are many more fossil families/genera/species of rays than currently described.  The researchers tend to put a lot of ray specimens into generic buckets.

 

Marco Sr.

[siteseer]

6 hours ago, MarcoSr said:

 

Jess

 

If you want to understand the different extant ray families/genera/species, understand the terminology used to describe extant rays, see a write-up on each currently identified extant ray, and maybe ID an extant ray, Last  et al (2016) is a great book.  This book did help tremendously with the ID of the e-bay taxidermy rays.  However it doesn't address teeth much at all other than tooth counts.  Line drawings of a few teeth would have really made the book much more useful.  Also features of the caudal stings and the denticles, thorns and thornlets aren't really addressed.  The lead-ins to each family are really useful to understand the unique features of the extant rays in each family.  Below are two typical species ID pages from “Last, White, de Carvalho, Seret, Stehmann, Naylor 2016 Rays of the World” .  Each species has a single ID page like this.

 

 

 

Marco Sr.

 

 

Yes, that's the approach of publications on modern sharks and rays.  Teeth are mentioned or only generally described but rarely clearly figured.  It's because modern taxa are usually named by external soft anatomy - the color and shape of the body and/or the area they inhabit.  In paleontology only the hard parts are preserved.  It's also unfortunate that ray fossil researchers don't write mainstream publications so there is little in the way of references for fossil collectors though that is admittedly a relatively tiny audience to target.

 

A couple of years into my own fossil collecting, I started to specialize in sharks and was not thinking of rays too, but then I started going to Sharktooth Hill Bonebed localities, finding lots of ray teeth (primarily dasyatid teeth) and I reconsidered.  I realized having ray fossils from other sites would help me understand what I was finding there - something for comparison.  It got me thinking about the wider fauna too so I started keeping at least a little of everything I found.

 

Ray fossils are generally not high on the list of collector interests even among shark tooth collectors.  Ray material is often quite inexpensive and I have even given some nice specimens when other collectors have found I was interested in it.

 

Jess

 

[siteseer]

2 hours ago, Coco said:

Hi,

 

I have the Last & Stevens 1994, a used publication that cost me a lot of money 8 years ago... Good book but I haven't a lot of australian jaws !

 

Coco

 

Hi Coco,

 

Yes, it's never been cheap.  I've kept an eye open for a bargain price for that but haven't seen it yet.  I don't have any Australian jaws either but I still want the book.

 

Jess