The ECPHORA The Newsletter of the Calvert Marine Museum Club Volume 35  Number 3 September 2020

Features  Zimmerman Completes Dora Zimmerman Completes Id and Sorting of Shell Identifications the Silverthorn Shell Collection  Variations in Stingray Tail Spines

Inside  President’s Column  Choptank Claw  Meg Recently Found  Portrait of Lincoln Dryden  Two-tailed Ecphora  Pliocene Otoliths  Minute Crab Found  Disney’s MONSTRO  Ammonite Found Locally  Squalodon Tooth Found  Dust-Extraction System  Dive Turtle  Bent and Pinched  CMM Freezer Mystery  CMM Fossil Club Field Trips and Meetings.

For three years, CMM volunteer, Dora Zimmerman has been identifying and sorting through modern seashells comprising the Silverthorn Collection. In so doing, she has volunteered for over 460 hours! Many thanks for “playing” in our shell collection.

CALVERT MARINE MUSEUM www.calvertmarinemuseum.com Continued on page 2…

2 The Ecphora September 2020

Greetings Club Members! Choptank Formation Crab Claw

I'm sure like many of you, you feel this year is going on forever and every time you think this is got to be the worst of it, something else happens. This has been one crazy year. I apologize that we are still unable to meet as a group for either meetings or on a field trip. I hope that changes soon. At least for now, the museum has reopened albeit on a limited basis. Many thanks to Stephen and the CMM staff for arranging for a virtual club meeting and lecture - I hope this is the last time we have to do that. I realize that for folks who aren't Calvert residents this has been a really hard year since the Taylor Swanson found this crab claw ( sp.) County decided to close all of their beaches to non- with lovely preservation, eroding from the Choptank County residents. This might have had the unintended Formation along Calvert Cliffs. Text and photo side benefit of finding new places to hunt, so I hope submitted by Taylor Swanson. ☼ everyone was able to get out and find one or two goodies to add to their collection. That said, we've still been able to add some Meg Recently Found excellent to the CMM's permanent collection this year. A few things have been quarried from Matoaka and other specimens from various beaches. The Cliffs are still producing and fossils will be there for us when Covid-19 finally becomes contained. As for club business, we usually hold our elections in April, but for now, I foresee this being pushed out until we can finally meet in person and have a club-meeting quorum. We do need someone to step up for the Vice President role. Grenda Dennis will be stepping down to focus on home improvements, so if anyone is willing to serve in that role or on our Nominating Committee please let me know.

Stay safe and happy hunting.

Submitted by Paul Murdoch. ☼

Members, You Can Now Renew Your Fossil Club Membership

Online. Stephen Groff found this meg recently along the https://www.calvertmarinemuseum.com/FormCenter cliffs. Photo by S. Godfrey. ☼ /Fossil-Club-23/Fossil-Club-Membership-85

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Portrait of Lincoln Dryden Ecphora, Trauma Survivor

You may already be aware of this but the well-known photographer Audrey Bodine took a photo of Lincoln Found by Taylor Swanson along the shoreline near Dryden at the Calvert Cliffs nuclear plant project in Matoaka Cabins (St. Leonard, Calvert Cliffs), this the 1960s. It shows Lincoln inside the trailer we used Ecphora meganae is a trauma survivor. Likely picked as our office. Each of us also had a helmet provided up and crushed in the mouth of a hungry fish, this by BG&E we were supposed to wear during our shell was broken in three distinct spots along the main activities. I like this image of him as he is younger and whorl, breaking through to the central columella. For working at the cliffs. Text and photo submitted by Ralph Eshelman. ☼ reasons unknown, the hungry predator did not finish its meal that day and left this Ecphora battered and broken. However, the Ecphora did not die, and with Map shows you Where Your time the outer whorls healed. However, the shell pieces did not realign, disrupting the growth of the Hometown was on Earth Millions siphonal canal. To compensate, the Ecphora grew a of Years Ago new siphonal canal giving it the appearance of having two “tails”. Text and photo submitted by Taylor https://www.cnn.com/2020/08/30/us/map- Swanson. ☼ hometown-earth-continental-drift-scn- trnd/index.html Editor’s note: The forked “tail” end of the Ecphora is actually the front (i.e. anterior) end of the shell. Submitted by Perry Hampton. ☼

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Pliocene Otolith Assemblage Sperm Whale in Pinocchio

Please find below an address to download a PDF of a recent publication on the first Pliocene otolith assemblage from the Gulf Coastal Plain of the USA. While Pliocene otoliths are abundant in the Atlantic Coastal Plain, California (USA), and the Caribbean/Central and South America, these are the first otoliths described from the Gulf Coastal Plain. I hope you enjoy the publication found at the following address: https://www.tandfonline.com/eprint/XADIBPY8VM CERJWEFRJE/full?target=10.1080/08912963.2020. 1773457

Submitted by Gary L. Stringer, Ph.D. Professor Emeritus of Geology University of Louisiana at Monroe Monroe, Louisiana 71209-0550

☼ In this childhood Disney book of mine (that I was flipping through the other day ), I was reminded of Minute Crab found along MONSTRO, giant sperm whale and terror of the deep. Calvert Cliffs

George Oliver found this tiny crab in a concretion along Calvert Cliffs. It’s the smallest one I’ve ever What caught my attention were its large teeth in the seen. Photo by S. Godfrey. ☼ upper jaw. The living sperm whale (Physeter macrocephalus) only has very tiny vestigial teeth in its Newsletter website: http://calvertmarinemuseum.com/204/The-Ecphora-Newsletter 5 The Ecphora September 2020 upper jaw, quite unlike the massive ones rendered Many years ago, Jim Jorden found this partial here by a Disney artist. This rendering of MONSTRO ammonite fossil on the beach at what is now Elm’s reminds me of the giant Miocene sperm whale from Beach Park (in St. Mary’s County south of Calvert Peru, Livyatan melvillei (below). Image from: Walt Cliffs). It is puzzling that an ammonite of Mesozoic Disney’s Pinocchio Picture Book, Grosset & Dunlap, appearance would be found on a beach that is devoid , 1939. of sediments from that geologic era. We have not been able to figure out what kind of ammonite this is, so if anyone knows, please let me know ([email protected]). Photo by S. Godfrey. ☼

Lovely Squalodon Tooth Found

Sculpted restoration of the skull of Livyatan in the Museum of Natural History in Lima, Peru. Notice the giant teeth in both jaws, just like in Disney’s 1939 rendering of MONSTRO. Livyatan was first discovered in November 2008. Text and photos submitted by S. Godfrey. ☼

Ammonite Found along the Bay

Stephen Groff found this Squalodon tooth recently along the cliffs. Photo by S. Godfrey. ☼

HISTORY OF PALEONTOLOGY WITHIN THE NATIONAL PARK SERVICE

Here is a link to a new website dedicated to the History of NPS Paleontology. https://www.nps.gov/subjects/fossils/history-of- paleontology-in-the-national-park-service.htm

Submitted by Dr. Vince Santucci. ☼

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Dust-Extraction System Recently Stephen Groff working to install a bracket to hold one of two arms of the dust-extraction system. Installed in CMM Fossil Preparation Lab

Under the guidance of CMM Paleo Collections Manager John Nance, a new dust- collection system has been installed in our fossil preparation lab. We benefitted greatly from volunteer help from Pat Gotsis, Bill Prochownik, and Stephen Groff. Thank you all very much for contributing so much to the Museum!

John Nance (in Covid attire) next to one of two arms of the dust and fume extraction system just installed in our fossil preparation lab. Photos by S. Godfrey. ☼

Shark Researchers Size Megalodon Again https://www.bbc.com/news/uk-wales-54011932

Submitted by Mike Ellwood. ☼

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Dive Turtle Bent and Pinched Coprolite

Mike Ellwood found this coprolite in the Aurora Mine (formerly known as the Lee Creek Mine) some years ago. It would be nice to know what produced it. Photo by S. Godfrey. ☼ Mystery in the CMM Freezer

Here, fossil preparation lab volunteer, Mike Ellwood is gingerly removing sediment from around the remains of a fossil turtle that Aaron Alford and Walt Johns collected from the bed of a river in . Okay, so I know it’s not fossil-related, but it’s so The underwater sediments around the bone were so bizarre I had to include it here. The other day, I filled soupy that Aaron had to exercise great care in the ice cube tray with regular tap water and put the jacketing this specimen. It is tentatively identified as tray in the staff lunchroom freezer. The next day when Trachyaspis lardyi. Photo by S. Godfrey. ☼ I came to fetch ice cubes to cool my drink, I noticed several ice cubes with tiny “stalagmites” protruding

Newsletter website: http://calvertmarinemuseum.com/204/The-Ecphora-Newsletter 8 The Ecphora September 2020 from the main body of the cube. There was nothing Saturday, November 21, 2020, ZOOM Fossil Club put in the tray other than tap water. Nothing to draw meeting (NOTE THE CHANGE OF DATE) at 2 the water out into this tiny unicorn horn. I have no pm followed at 2:30 by a public lecture to be given by idea what would have caused these spines to form. I Dr. Kay Behrensmeyer (Smithsonian, Department have never seen this phenomenon before. Has anyone of ). She will speak on her work on seen anything like this before? The only thing I can ; how a fossil becomes a fossil, with figure is that it has something to do with the fact that amazing stories from the fossil record. as water freezes it expands. Photo by S. Godfrey. ☼ Saturday, November 28, 2020, Odessa, DE. This is CALVERT MARINE MUSEUM a John Wolf Memorial Trip. Special COVID instructions: Wear a mask (& wear it FOSSIL CLUB EVENTS properly) except when you are all alone or with Saturday, October 17th, 2020, meet at the park at immediate family. Park your car at least a full car 10:00 AM, Purse State Park. Aquia Formation, Late length behind the car in front. We will be in a big Paleocene. Sign up by email, field (soybean this year) and you will have no trouble [email protected], the earlier the better, but by staying 20 yards apart. the Thursday before the trip. Limit 10. Special Sign up by email, the earlier the better but no COVID notes: Don't bunch up, not in the parking lot, later than Thanksgiving, [email protected]. not on the path to the river, not along the river. Wear And a special note: This is a working farm. If the a mask (& wear it properly) until you are all alone & harvest isn't in, we will have to postpone the trip. This then keep it ready to put back on. Low tide (at year we will meet directly at the farm (directions at Liverpool Point) 1:53 PM -0.1 sign up), starting at 10:00 AM (but don't go to the This site is on the Potomac River in Charles farm early) County, MD. Well known for abundant crocodile, We’ll walk the fields and collect petrified ray, Otodus sp., and Striatolamia sp. teeth, and wood (cypress), probably originally deposited in the internal molds of the gastropod Turritella sp. (more Cretaceous or Paleocene Rancocas Group and later than you can carry out). Access to the site requires a redeposited in a Pleistocene bed. (Thanks to Dr. moderate hike through the woods, and sometimes Earl Manning, DVPS member, for correcting our rather strenuous hiking and climbing over trees along previous description of the petrified wood as being the water's edge. When we get to the Potomac, we will Pleistocene.) No special equipment is necessary; in all turn left and walk south along the river to the most fact, you should leave your tools at home so that we productive areas (there will be small sand teeth do not do anything to cause erosion on this low-till all along the way). We’ll meet at the park at 10:00. farm. Here's a link to a nice write up about one of our Take a look at what you can trips to a nearby site: find: http://www.fossilguy.com/sites/potomac/index http://viewsofthemahantango.blogspot.com/2011/08/ .htm petrified-wood-from-delaware.html ☼ You can pull up a map on MapQuest or Google Maps by entering Liverpool Point Rd & Riverside Rd in Nanjemoy MD 20662 (the street Fossil Hunting in a Creek address just past the intersection is 9250 Riverside Rd, Nanjemoy, MD 20662). The parking area is 1.8 miles Post-Hurricane Fossil Hunting in a Creek | Shark south of that intersection. (Riverside Rd is MD Rt 224 Teeth and Whale Bones at that point). If you are not familiar with the park, I really recommend that you make a map. Submitted by Walt Johns. ☼ Don't look for street address signs but if your GPS is up to date, you can use this address for the parking area where we will meet: 10124 Riverside Rd., Nanjemoy, MD 20662.

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Part of an exhibit mural at the Calvert Marine Museum featuring extant stingrays, created by former CMM artist Tim Scheirer. © CMM

Variations in Stingray Tail Spines

By Stephen J. Godfrey, Yasemin I. Tulu, and Bretton Kent

Abstract—The tail spine in myliobatiform chondrichthyans (generally known as stingrays) is a modified and very elongate dermal denticle. Here we describe developmental variations in Miocene and Pliocene myliobatiform tail spines including supernumerary denticles scattered over the enameloid ridges, supernumerary rows of denticles, individual denticles further subdivided into multiple smaller denticles, serrations missing from where they would be expected along the well-defined lateral margins of the spine, and wrinkled enameloid ridges at the base of the spine. The factors responsible for tail spine variability are not presently known but could conceivably arise either from (a) mutations to regulatory genes controlling spine formation or (b) trauma to the developing spine or surrounding tissues prior to, or during mineralization.

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Introduction From the time of Aristotle (384-322 BCE), cartilaginous fishes of the order () have been known to be biotoxic (Halstead, 1988). Their toxicity derives from a delivery apparatus, of which an elongate tail spine (i.e., sting) is the most conspicuous element. Captain John Smith is one famous survivor, having been struck in the wrist by the spine of a “Thornback” when he was removing the fish from his sword (Mumford, 1903; Halstead, 1988). The venom apparatus is functionally a defensive striking organ—these rays are preyed upon by (and people with swords)—consisting of a bilaterally retroserrate dentinal spine with its enveloping integumentary sheath which includes the venom-producing glands (Halstead, et al., 1955; Halstead, 1988). The spine is a greatly enlarged dorsoventrally flattened dermal denticle that tapers gradually to a sharp point (Daniel, 1934; Bigelow and Schroeder, 1953), (Fig. 1A). It is composed of an inner core of vasodentine and a thin outer (dorsal and ventrolateral) enameloid layer (Halstead, 1988). The dorsal surface of the spine usually exhibits longitudinal grooves and corresponding ridges (Fig. 1B and C) whereas the ventral side of the spine is either without enameloid ridges (Fig. 1D) or sometimes presents a median ventral ridge that separates the bilateral glandular grooves, which in life house the venom-producing tissue. As the spine develops, it is enveloped in an epidermal sheath (Carvalho et al., 2004). This sheath contains blood vessels ventrally, adjacent to the longitudinal ridges, and glandular epithelium towards its periphery, which is responsible for the production of venom (Halstead and Modglin, 1950; Halstead, 1970). Some of these features vary taxonomically (Schwartz, 2005, 2007, 2008a, 2008b, 2009; Cuny and Piyapong, 2007). In life, the basal end of the spine is usually firmly anchored in a dense collagenous network of the dermis on the dorsal side of their tail (Halstead et al., 1955). Individuals can possess as many as five spines representing the retention of successive generations of spines (Fig. 1B) (Grudger, 1914). New spines erupt from below an existing one. At parturition, neonate stingrays possess a caudal sting (although present, it is slightly less acute in embryos) (Carvalho et al., 2004). In most myliobatiform tail spines, the retroserrations are limited to the well-defined lateral margins (Fig. 1). However, some Miocene and Pliocene stingray spines exhibit supernumerary serrations in various stages of development from tiny incipient ridges to fully formed serrations scattered widely over many of the enameloid longitudinal ridges medial to the marginal serrations. During the course of this preliminary survey, it became evident that pathologies were also present on stingray tail spines. Gudger (1933) described unusual dentitions in rays, but as yet, this has not been done for their tail spines. Therefore, the purpose of this note is to document variations in myliobatiform caudal spines found in Miocene and Pliocene specimens. The underlying developmental processes whereby these variations form is not presently known, and beyond the scope of this brief report. Specimens Examined Hundreds of isolated fossilized stingray tail spines are held in the collections of the National Museum of Natural History, the Smithsonian Institution (USNM) and the Calvert Marine Museum (CMM). Most of these spines were surface collected from spoil piles of Miocene and Pliocene-age sediments within the Aurora Mine (formerly known as the Lee Creek Mine), Aurora, , U.S.A., and from Neogene sediments elsewhere along the Atlantic Coastal Plain. Ray (1983, 1987), Ray and Bohaska (2001), and Ray et al. (2008) document the abundant and diverse Neogene biota within the Aurora Mine. These and the spines of extant stingrays were examined in order to describe some of the variations that they can present. Although the

Newsletter website: http://calvertmarinemuseum.com/204/The-Ecphora-Newsletter 11 The Ecphora September 2020 expression of individual variation varies greatly from one spine to another, they appear to represent variations on a smaller number of themes.

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Figure 1. A. Tail spine from an extant undetermined myliobatiform. B. USNM 21345 dried roughtail stingray (Dasyatis centroura) tail section showing three generations of overlapping tail spines. C. CMM-V-3959, fossilized undetermined myliobatiform caudal spine in dorsal view recovered from the Calvert Beach Member of the Calvert Formation (Miocene, Chesapeake Group) along the Rappahannock River, Virginia. D. CMM-V-3959 in ventral view. The enameloid dorsal surface exhibits interweaving longitudinal grooves and corresponding ridges. Retrorse denticles line the lateral margins. In most myliobatiform tail spines, these denticles are limited to the well-defined lateral margins. CMM-V-3959 lightly dusted with sublimed ammonium chloride. Scale bar equals 10 mm for C & D.

Results The following general categories were observed (these categories do not necessarily correspond to an equal number of underlying developmental causes/pathways):

1. Supernumerary (i.e., extra) rows of denticles (Figs. 2 & 3A–B). Both normally shaped and deformed denticles in all stages of development occur on the dorsal enameloid side of the spine. These variably- shaped denticles occur in supernumerary rows of denticles positioned medial to the marginal row. This feature often manifests itself in the splitting of the normal retrorse dentate margin into two marginal rows one immediately adjacent to the other. No myliobatiform spine exhibited a complete splitting of a denticle row to produce a supernumerary row of denticles running the full length of the spine; all supernumerary rows were partial. Denticles appear to form initially from a ridge primordium (Amesbury and Snelson, 1997; Johansson et al., 2004), (Fig. 2B). The denticles then mature at regular intervals along this ridge from the proliferation and differentiation of denticle primordia. It has been proposed, that in chondrichthyans, each tooth and scale germ is surrounded by a field that prevents the induction of a new tooth or scale; however, growth of germ cells outside the inhibition field allows for the induction of new teeth or scales in the dental lamina and skin respectively (Soler-Gijón, 1999). This inhibition-induction mechanism would account for the uniform spacing between normal denticles along the lateral margins of the tail spine. In reference to the orientation of the scattered denticle ridge primordia, their long axis is more often than not, aligned with the long axis of the spine, but they can also occur at right angles to it, or any angle in between (Fig. 2). The variable orientation of these individual denticle ridge primordia could have resulted from the physical displacement of denticle germ cells from their original lateral position along the spine. As further evidence of the misaligned orientation of denticle primordia, some deformed but mature denticles point distally instead of proximally (i.e. they are non-retrorse denticles). 2. Lateral denticles missing from sections of the spine (Fig. 2A & B). This developmental variation is easily recognized when series of denticles are missing from the lateral margin of an otherwise dentate spine. It is reasonably assumed that in the absence of the originating developmental anomaly/pathology or trauma, denticles would have been present as evidenced by the presence of normal denticles on the opposite side of the spine. The absence of denticles is presumed to result from the physical removal or destruction of the induction stimulus or denticle germ cells in that area.

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Figure 2. A. CMM-V-3960, an incomplete undetermined myliobatiform tail spine in dorsal view. The spine was collected from along the Rappahannock River in Virginia from the Calvert Formation (Miocene, Chesapeake Group). B. Close-up view of the distal end of CMM-V-3960 showing both marginal denticles and displaced supernumerary denticles in all stages of development originating from ridge primordia. C. Enlarged view of the proximal end of CMM-V-3960 showing the grotesquely swollen and supernumerary dentate ridges. D. CMM-V- 1925, the proximal end of an incomplete spine in dorsal view. Duplicate (i.e. split) supernumerary rows are present in this specimen, as are variably-shaped and multi-crowned denticles. Spines lightly dusted with sublimed ammonium chloride. Scale bars equal 10 mm.

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Figure 3. Fossilized undetermined myliobatiform caudal spines. A. USNM 619504 in dorsal view showing supernumerary rows of retrorse denticles. B. USNM 619505 showing a short supernumerary row of the denticles centrally. Notice the enlarged distal-most denticle, a condition also seen in CMM-V-1925 (Fig. 2D). C. USNM 619506 showing the deformed multi-crowned spines along its lateral margin. D. USNM 619507 showing the wrinkled enameloid, increasingly obvious towards the base of the spine (i.e., towards the bottom of the photo). Only D was lightly dusted with sublimed ammonium chloride. Scale bars equal 10 mm.

3. Segments of one or more of the enameloid longitudinal ridges grotesquely enlarged (Fig. 2A & C). In this infrequently encounter variation, swollen proliferative growths occupy one or more of the enameloid ridges. Portions of these ridges are wrinkled and furrowed, and may exhibit deformed and disoriented denticles. These hypertrophied ridges may have originated as the more frequently encountered supernumerary denticle rows from the splitting of dermal denticle row protogerms, proliferating in the absence of the usual inhibition mechanisms. 4. Wrinkled enameloid ridges at the base of the spine (Fig. 3D). In this variation, instead of the longitudinal enameloid ridges being essentially smooth to the base of the spine, the wrinkled enameloid appears as though the spine (enameloid) was compressed longitudinally or bent (flexed) dorsally early on during its formation, possibly the result of physical compression. Subsequent mineralization of the spine preserved the wrinkled ridges. 5. Tip of a denticle bifurcates or is further subdivided displaying multiple crowns (this includes larger deformed denticles in which they are presumed to be this way because during their embryonic formation, there was incomplete separation between adjacent denticles), (Figs. 2D & 3C). In their vast majority, each pointed retrorse denticle arises from a single base. However, in some denticles, with either a normal or an enlarged base, their crown exhibits two or more tips. Perhaps multi-crowned denticles develop when the local inhibition-induction field is disturbed resulting in single or multiple subdivision and proliferation of denticle crown tissue. 6. USNM 619508 (Fig. 4) is difficult to interpret. The long axis of the base of the spine is presumed to parallel the long axis of the tail for two reasons. The base of the myliobatiform tail would not have been wide enough to accommodate such a wide and essentially flat-bottomed spine-base. Furthermore, most of the denticles align with the length of the base of the spine as they would in a typical tail spine. At about the midpoint in its length, the spine does present an apex that is skewed to one side. We do not know if this apex represents what should have been the original apex of the spine had it developed normally, or some point along the spine that was drawn out in this way. Alternatively, this spine could represent the fusion of two spine primordia or one spine that might have been split lengthwise. If either of these occurred, then we would interpret the apex of this curious spine as the area where the distal ends of the two spines met and fused, or the apex of the spine in spite of the base having been drawn out so much.

Discussion The factors responsible for the developmental variability seen in the tail spines are not presently known, but they could conceivably have arisen from either (a) mutations to regulatory genes controlling spine formation or (b) physical trauma to the incipient spine or surrounding tissues prior to, or during mineralization. To date, no research has been done specifically on the gene regulation of caudal spine development in rays. Caudal spines are thought to develop by a mechanism similar to that of dermal denticles (Johansson et al., 2004), and the Dlx gene complex is known to be active during both tooth and dermal denticle development (Debiais-Thibaud et al., 2011).

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Figure 4. USNM 619508, a Pliocene myliobatiform caudal spine collected from the Aurora Mine, Aurora, N.C. Scale bar equals 10 mm. Specimen lightly dusted with sublimed ammonium chloride.

A mutation in the regulatory Dlx, or associated, gene complexes could produce anomalies that likely would be symmetrical about the midline of the tail spine (e.g., Fig. 3C-D). Variability in denticles and ornamentation arising through damage to the spine or generative tissues would probably be irregular and asymmetrical (e.g., Figs. 2, 3 & 4). The location of the developing caudal spine on the dorsal surface of the base of the tail adjacent to an existing unsheathed spine, used in a defensive capacity, could account for variability (or pathologies) arising from physical trauma. You may have stingray tail spines in your collection. Next time you look them over, notice the developmental variability that they can exhibit.

Acknowledgements.—This effort is dedicated to the memory of Jeff Sparks who collected and donated two stingray tail spines (CMM-V-3959 [Fig. 1C–D] and CMM-V-3960 [Fig. 2A–C]) to the Calvert Marine Museum. Newsletter website: http://calvertmarinemuseum.com/204/The-Ecphora-Newsletter 16 The Ecphora September 2020

Those specimens inspired this work. The other figured specimens were collected by the late Peter (Pete) J. Harmatuk; many thanks! J. R. Nance (CMM), D. Bohaska (USNM) and S. Raredon (USNM) kindly provided liberal access to fossil and modern stingray specimens in their care. The late Dr. John Pojeta (USNM) welcomed us to his lab where some of the fossil tail spines were whitened with sublimed ammonium chloride to increase photographic contrast. An earlier version of this manuscript benefited greatly from a review by Dr. Jim Bourdon. SJG and YIT received funding from the Calvert County Board of County Commissioners, the citizens of Calvert County, Maryland, and the Clarissa and Lincoln Dryden Endowment for Paleontology at the Calvert Marine Museum.

References Amesbury, E. and Snelson, Jr., F.F. 1997. Spine Replacement in a Freshwater Population of the , Dasyatis sabina. Copeia 1997(1): 220–223. Aschliman, N., Claeson, K.M., and McEachran, J.D. 2004. Phylogeny of Batoidea; pp. 57–95 In: J.C. Carrier, Musick, J.A., and Heithaus, M.R. (eds.), Biology of Sharks and Their Relatives (2nd ed.). CRC Press, Boca Raton, . Bigelow, H.B. and Schroeder, W.C. 1953. Fishes of the western north Atlantic. Part II. Sawfishes, guitarfishes, skates, rays and chimaeroids. Memoirs of the Sears Foundation for Marine Research 2, xv 1 588 pp. Carvalho, M.R., Maisey, J.G., and Grande, L. 2004. Freshwater stingrays of the Green River Formation of Wyoming (Early Eocene), with the description of a new genus and and an analysis of its phylogenetic relationships (Chondrichthyes: Myliobatiformes). Bulletin of the American Museum of Natural History 284, 136 pp. Cuny, G. and Piyapong, C. 2007. Tail spine characteristics of stingrays (Order Myliobatiformes): A comment to Schwartz (2005). Electronic Journal of 1: 15–17. Daniel, J.F. 1934. The elasmobranch fishes, 3rd ed. University of California Press, Berkeley, California. Debiais-Thibaud, M., Oulion, S., Bourrat, F., Laurenti, P., Casane, D., and Borday-Birraux, V. 2011. The homology of odontodes in gnathostomes: insights from Dlx gene expression in the dogfish, Scyliorhinus canicula). BMC Evolutionary Biology 11: 307–320. Evans, H.M. 1916. The poison-organ of the sting-ray (Trygon pastinaca). Proceedings of the Zoological Society of London 1–448. Gudger, E.W. 1914. History of the spotted eagle ray, Aëtobatus Narinari, together with a study of its external structures. Papers, Carnegie Institution of Washington Tortugus Laboratory, 6(12): 241–323, 10 plates. Gudger, E.W. 1933. Abnormal dentition in rays, Batoidei. Journal of the Elisha Mitchell Society 49(1): 57–96 Halstead, B.W., Ocampo, R.R., and Modglin, F.R. 1955. A study on the comparative anatomy of the venom apparatus of certain North American stingrays. Journal of Morphology 97(1): 1–21. Halstead, B.W., and Modglin, F.R. 1950. A preliminary report on the venom apparatus of the Bat-Ray. Copeia 3: 165–175. Halstead, B.W. 1988. Poisonous and Venomous Marine of the World. The Darwin Press Inc., 1, 168 pp. Johansson, P.K.E., Douglass, T.G., and Lowe, C.G. 2004. Caudal spine replacement and histogenesis in the Round Stingray, Urobatis halleri. Bulletin of the Southern California Academy of Science 103(3): 115– 124. Marmi, J., Vila, B., Oms, O., Galobart, À., and Cappetta, H. 2010. Oldest records of stingray spines (Chondrichthyes, Myliobatiformes). Journal of 30: 970–974. Mumford, J.G. 1903. A narrative of medicine in America. J.B. Lippincott, Philadelphia, 508 pp. Purdy, R.W., Schneider, V.P., Applegate, S.P., McLellan, J.H., Meyer, R.L., and Slaughter, B.H. 2001. The Neogene sharks, rays, and bony fishes from Lee Creek Mine, Aurora, North Carolina; 71–202. In: C.E.

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Ray and Bohaska, D.J. (eds.), Geology and Paleontology of the Lee Creek Mine, North Carolina, III. Smithsonian Contributions to Paleobiology 90. Smithsonian Institution Press, Washington, DC. Ray, C.E. (ed.). 1983. Geology and Paleontology of the Lee Creek Mine, North Carolina, I. Smithsonian Contributions to Paleobiology 53: 1–529. Ray, C.E. (ed.). 1987. Geology and Paleontology of the Lee Creek Mine, North Carolina, II. Smithsonian Contributions to Paleobiology 61: 1–283. Ray, C.E., and Bohaska, D.J. (eds.). 2001 Geology and Paleontology of the Lee Creek Mine, North Carolina, III. Smithsonian Contributions to Paleobiology 90: 1–365. Ray, C.E., Bohaska, D.J., Koretsky, I.A., Ward, L.W., and Barnes, L.G. (eds.). 2008. Geology and Paleontology of the Lee Creek Mine, North Carolina, IV. Virginia Museum of Natural History Special Publication 14: 1–517. Schwartz, F.J. 2005. Tail spine characteristics of stingrays (Order Myliobatiformes) found in the northeast Atlantic, Mediterranean, and Black Seas. Electronic Journal of Ichthyology 1: 1–9. Schwartz, F.J. 2007. Tail spine characteristics of stingrays (Order Myliobatiformes) frequenting the FAO fishing area 61 (20°N 120°E - 50°N 150°E) of the northwest Pacific Ocean. Raffles Journal of Zoology 14: 121– 130. Schwartz, F.J. 2008a. A survey of the tail spine characteristics of stingrays frequenting African, Arabian to Chagos-Maldive Archipelago waters. Smithiana Bulletin 8: 41–52. Schwartz, F.J. 2008b. A survey of the tail spine characteristics of stingrays frequenting Indo-Pacific Ocean areas between the International Date Line and the Chagos Archipelago-Maldive Islands. Journal of the North Carolina Academy of Science 124(2): 27–45. Schwartz, F.J. 2009. A survey of the tail spine characteristics of stingrays frequenting Western and South American freshwater rivers. Journal of the North Carolina Academy of Science 125(2): 47–60. Soler-Gijón, R. 1999. Occipital spine of Orthacanthus (Xenacanthidae, Elasmobranchii): structure and growth. Journal of Morphology 242: 1–45.

Stephen J. Godfrey [[email protected]], Department of Paleontology, Calvert Marine Museum, P.O. Box 97, Solomons, Maryland 20688, U.S.A.,; and Research Associate, National Museum of Natural History, Smithsonian Institution, Washington, DC, 20560, U.S.A. Yasemin I. Tulu [[email protected]], 282 W 12th St., Holland, Michigan 49423, U.S.A. Bretton Kent [[email protected]}, College of Computer, Mathematical and Natural Sciences, Plant Sciences Building, University of Maryland, College Park, Maryland 20742, U.S.A. ☼

Newsletter website: http://calvertmarinemuseum.com/204/The-Ecphora-Newsletter 18 The Ecphora September 2020

CMMFC P.O. Box 97 Solomons, MD 20688

OR CURRENT RESIDENT

The Ecphora is published four times a year 2019 Names Email and is the official newsletter of the Calvert Marine Elected Museum Fossil Club. The Editor welcomes Officers & contributions for possible inclusion in the Volunteers* newsletter from any source. Submit articles, news President Paul [email protected] reports of interest to club members, field trip Murdoch reports, and/or noteworthy discoveries. All Vice- Grenda [email protected] opinions expressed in the newsletter are strictly those President Dennis of the authors and do not reflect the views of the club Treasurer Christa [email protected] or the museum as a whole. Copyright on items or Conant articles published in The Ecphora is held by Secretary Dave [email protected] originating authors and may only be reproduced with Bohaska the written permission of the editor or of the author(s) Membership Christa [email protected] of any article contained within. Chairperson Conant Editor* Stephen [email protected] Editor’s Address: Godfrey Stephen Godfrey Ph.D. Fall Trip Robert [email protected] Curator of Paleontology Leader* Ertman Calvert Marine Museum Spring Trip Robert [email protected] P.O. Box 97 Leader* Ertman Solomons, MD 20688 [email protected]

Many thanks to Mike Ellwood, and John Nance for proofreading this edition. Newsletter website: http://calvertmarinemuseum.com/204/The-Ecphora-Newsletter