New Paleontology Gallery Exhibit Soon to Open
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The Newsletter of the Calvert Marine Museum Fossil Club Volume 22 .Number 4 D~cember2007 New Paleontology Gallery Exhibit Soon to Open ... After years of planning and months of construction and installation, a new exhibit, nearing its birth now graces' the entrance, to our Paleontology Gallery. Designed by Exhibits Curator, James Langley, this superb addition to the Museum was made possible through funding from a CMM's resident artist, Tim Scheirer National Parks Service begins to apply the spiral Earth-history Gateways Grant and the time-line to the wall. Rachel Reese, Clarissa and Lincoln Dryden another member of the CMM Exhibit's Endowment for Department, completed the computer Paleontology. CMM Fossil graphic work. The new exhibit will also Club members donated feature video presentations, some of the fossils on geoanimations, and computer terminals for display. in depth information about thefossils. Tommy Younger (left) and Skip The mural includes cast replicas. It Edwards crafted the jewel-like is my desir.e to gradually replace armature that holds an original most of the casts with original oreodont skull now on display. Scalae Naturae ... fossils as donations and/or funds become available. CALVERT MARINE MUSEUM www.calvertmarinemuseum.com '~The Ecphora December 2007 Deinosuchus: Another Maryland "SuperCroc" Figure 2 shows life drawings of crocodile and alligator heads, at approximately the same scale as By: George F. Klein Figure 1. You will note the width of the alligator's head compared to that of the crocodile. In terms of skull width, Deinosuchus resembles an alligator Deinosuchus was a large crocodilian that more than a crocodile. Having a wider snout is a lived during the Late Cretaceous. It is among the characteristic of alligators. largest crocodilians to have ever lived, with a length approaching 40 feet and a weight estimated to be 9.5 tons (1). Deinosuchus fossils have been found in Maryland, in Prince George's County (3,6). Recent work by Schwimmer (1) places Deinosuchus close to the common ancestor of the alligator family. Figure 1 shows drawings of a Deinosuchus skull (lettering on the skull refers to the individual bones). You will note that with the jaws closed, teeth from both the upper and lower jaws are visible. Especially note the notch in the jaws just behind the premaxillary bone (labeled PM in the drawing, the tip of the snout). These are characteristics of crocodiles. sa PO PRF Figure 2: The head of a crocodile (left) compared to an alligator. Recently, a new discovery has extended the geographic range of this animal to the state of New Mexico. The Deinosuchus fossils were discovered in 1999 and only recently identified. Paul Sealey, a volunteer for the New Mexico Museum of Natural History (NMMNH), found them. The fossils were found close to the town of Farmington, in the northwest comer of the state near the "Four Comers" region. The fossils consisted of a section of the lower jaw, some teeth and scutes. The fossils have been prepared and are currently on display at the NMMNH in Albuquerque (2, 5). This is the first time Deinosuchus fossil have Figure 1: Two views of a Deinosuchus skull. been found in New Mexico. According to Club website: http://www.calvertmarinemuseum.com/cmmfc/index.html Club email: [email protected] - --- --------- ----- ---- -- --------- Schwimmer (1), Deinosuchus fossils have been Deinosuchus probably lived in nearshore, .identified from ten states. My research (3) indicates estuary, and salt marsh environments the way the Schwimmer seems to have missed one state, Salt Water Crocodile (Crocodylus porosus) of Maryland (believe it or not!). Therefore, the states Australia and the Pacific region does today. It is where Deinosuchus fossils occur are now: likely that it lived all up and down the East Coast of the US and along both shores of the WIS, probably (1) New Jersey Ref. (1) as far as what would have been the Canadian border, (2) Maryland Ref. (3) although its fossils may be lacking in certain areas as (3) Delaware Ref. (1) noted above. (4) North Carolina Ref. (1) To my knowledge, Deinosuchus fossil have (5) South Carolina Ref. (1) not been found in the Campanian Age WenonahlMt. (6) Georgia Ref. (1) Laurel Formations exposed at Big Brook and (7) Alabama Ref. (1) Ramanessian Brook of New Jersey. These represent (8) Mississippi Ref. (1) deepwater sediments. Deinosuchus remains have (9) Texas Ref. (1) been found at the famous Ellisdale, NJ site, in the (10) New Mexico Ref. (2) Marshalltown Formation. The fossils from Ellisdale (11) Wyoming Ref. (1) represent a near shore environment. Virginia, an East (12) Montana Ref. (1) Coast state lacking Deinosuchus remains, has exposed only Early Cretaceous formations. As you will recall, during most of the Schwimmer found evidence of Deinosuchus Cretaceous, the Western Interior Seaway (WIS) split predation on dinosaurs. A private collector in the Big North America from the Gulf of Mexico to the Bend area of Texas found hadrosaur vertebrae with Arctic. Occurrences of Deinosuchus fossils west of blunt bite marks on them. These big marks are the current Mississippi River are from what would probably too large to have been made by the other be the east facing shore of the WIS. The only crocodilians alive during the Cretaceous. occurrence of Deinosuchus from the west facing Photographs of these vertebrae are shown in shore is that from the state of Mississippi. reference 1. At 9.5 tons, Deinosuchus was heavier Interestingly, Deinosuchus and crocodilian than a T rex and any hadrosaur. fossils in general are lacking from the terrific marine Cretaceous formations of Kansas. I find the paucity of crocodile fossils from this state somewhat perplexing, as dinosaurs have been found in these marine exposures. Some of the dinosaurs found in Kansas are undoubtedly due to "float and bloat"-that is a dinosaur dies, was washed into a river and eventually into the WIS, floating due to bloating of its carcass as a result of internal bacterial decay. Then marine predators like sharks and mosasaurs probably scavenged it following which, the carcass sank to the bottom where it became fossilized. You would think that a crocodile would also become fossilized in Kansas by the same process. Deinosuchus fossils are found in late Cretaceous exposures (Campanian and possibly Maastrichtian Age, 83.0 - 65.4 million years old). Figure 3: Deinosuchus posterior tooth, basal The youngest formations in Kansas are 82 -83 diameter approx. 1.5". million years old (4) so this may explain the lack of Deinosuchus fossils from that state. Club website: http://www.calvertmarinemuseum.comlcmmfc/index.html Club email: [email protected] ¥k.'The-ill Ecphora December 2007 Thanks to Dewayne Varnum, President of the Stingray crusher plate from East Coast Fossil Club of Fayetteville, North Carolina (www.megalodon.net). Above is a Purse State Park photograph of a very large posterior Deinosuchus tooth, found at Elizabethtown, NC. Elizabethtown I found a nearly complete ray crusher plate has been the source of some of the most significant on Nov. 8, 2007 on the Potomac shoreline at Purse Deinosuchus finds on the East Coast. State Park. The plate was actually embedded in a In addition to the very large Miocene layer of Aquia Formation sediment about six inches crocodile Gavialosuchus (or Thecachampsa) found below the surface of the water when I stumbled upon at Calvert Cliffs,. during the Cretaceous, Maryland it. I'm kind of sorry that I didn't walk back to the was home to another, even larger crocodilian, truck to retrieve a shovel to remove a slab of Deinosuchus. sediment so that it could be uncovered "in situ." In stead I hacked it out in four pieces with my wire References mesh scoop-on-a-handle. (1) King 0/ the Crocodylians by: D. R. Schwimmer Indiana University press, Bloomington, IN 2002 (2) http://www.abqtrib.com/newsI2006/janl03/bo na- fide-bony- find! (3) Hartstein, E, L. Decina and R. Keil "A Late Cretaceous (Severn Formation) Vertebrate Assemblage from Bowie, Maryland" The Mosasaur, Vol. 6, p. 17 (May 1999) (4) Oceans o/Kansas by: MJ. Everhart Indiana University Press, Bloomington, IN 2005 (5) www.nmnaturalhistory.org/science!geoscienc e/collecting fossils/disp1ay1.html (6) Collecting Fossils in Maryland by: J. D. Glaser Johns Hopkins University Press, Baltimore, MD 1995 ?Oldest Record of Multicellular The plate (Myliobatis copeanus) measures 3.25 Life, Named Fracto/usus misrai inches long by 2.25 inches wide and contains 10 rows o/plates! Photo by B. Hargreaves. A fossil found in Canada believed to be 565 Submitted by Bruce Hargreaves -P million years old has been named after the Indian geologist, Shiva Balak Misra, who found it. http://news.bbc.co.uk/2/hi/south asia17000829.stm Submitted by Yasemin Tulu -P Club website: http://www.calvertmarinemuseum.comlcmmfc/index.html Club email: CMMFossilclub@hotmaiLcom ~~\::The-s""· Ecphora December 2007 Locals know the area around the Bear Valley The Carboniferous Challenge: mine as a recreation site for off-road vehicles and a Seed Fems, Scale Trees, and place to swim in some of the water-filled pits. Horsetails Geologists know it as the site of "Whaleback", an exposed example of the Allegheny orogeny (mountain building) and a famous natural structure By: Tom Farrell & Bruce Hargreaves that is visited by college geology students from' around the globe. In fact, it's "paradise lost" for While most field trips sponsored by the many geologists because it contains examples of CMMFC focus on the hunt for extinct marine life three types of faults, plus folds, joints, cleavage, associated with the Miocene epoch, occasionally we lineations, and slickenlines, not to mention numerous explore areas along the Eastern seaboard containing varieties of terrestrial and marine sediments, all fossil-bearing sediments from other eras.