Jump to content

Search the Community

Showing results for tags 'ostracoda'.



More search options

  • Search By Tags

    Type tags separated by commas.
    Tags should be keywords or key phrases. e.g. carcharodon, pliocene, cypresshead formation, florida.
  • Search By Author

Content Type


Forums

  • Fossil Discussion
    • General Fossil Discussion
    • Fossil Hunting Trips
    • Fossil ID
    • Is It Real? How to Recognize Fossil Fabrications
    • Partners in Paleontology - Member Contributions to Science
    • Questions & Answers
    • Fossil of the Month
    • Member Collections
    • A Trip to the Museum
    • Paleo Re-creations
    • Collecting Gear
    • Fossil Preparation
    • Member Fossil Trades Bulletin Board
    • Member-to-Member Fossil Sales
    • Fossil News
  • Gallery
  • Fossil Sites
    • Africa
    • Asia
    • Australia - New Zealand
    • Canada
    • Europe
    • Middle East
    • South America
    • United States
  • Fossil Media
    • Members Websites
    • Fossils On The Web
    • Fossil Photography
    • Fossil Literature
    • Documents

Blogs

  • Anson's Blog
  • Mudding Around
  • Nicholas' Blog
  • dinosaur50's Blog
  • Traviscounty's Blog
  • Seldom's Blog
  • tracer's tidbits
  • Sacredsin's Blog
  • fossilfacetheprospector's Blog
  • jax world
  • echinoman's Blog
  • Ammonoidea
  • Traviscounty's Blog
  • brsr0131's Blog
  • brsr0131's Blog
  • Adventures with a Paddle
  • Caveat emptor
  • -------
  • Fig Rocks' Blog
  • placoderms
  • mosasaurs
  • ozzyrules244's Blog
  • Sir Knightia's Blog
  • Terry Dactyll's Blog
  • shakinchevy2008's Blog
  • MaHa's Blog
  • Stratio's Blog
  • ROOKMANDON's Blog
  • Phoenixflood's Blog
  • Brett Breakin' Rocks' Blog
  • Seattleguy's Blog
  • jkfoam's Blog
  • Erwan's Blog
  • Erwan's Blog
  • Lindsey's Blog
  • marksfossils' Blog
  • ibanda89's Blog
  • Liberty's Blog
  • Liberty's Blog
  • Back of Beyond
  • St. Johns River Shark Teeth/Florida
  • Ameenah's Blog
  • gordon's Blog
  • West4me's Blog
  • West4me's Blog
  • Pennsylvania Perspectives
  • michigantim's Blog
  • michigantim's Blog
  • lauraharp's Blog
  • lauraharp's Blog
  • micropterus101's Blog
  • micropterus101's Blog
  • GPeach129's Blog
  • nicciann's Blog
  • Olenellus' Blog
  • nicciann's Blog
  • maybe a nest fossil?
  • Deep-Thinker's Blog
  • Deep-Thinker's Blog
  • bear-dog's Blog
  • javidal's Blog
  • Digging America
  • John Sun's Blog
  • John Sun's Blog
  • Ravsiden's Blog
  • Jurassic park
  • The Hunt for Fossils
  • The Fury's Grand Blog
  • julie's ??
  • Hunt'n 'odonts!
  • falcondob's Blog
  • Monkeyfuss' Blog
  • cyndy's Blog
  • pattyf's Blog
  • pattyf's Blog
  • chrisf's Blog
  • chrisf's Blog
  • nola's Blog
  • mercyrcfans88's Blog
  • Emily's PRI Adventure
  • trilobite guy's Blog
  • xenacanthus' Blog
  • barnes' Blog
  • myfossiltrips.blogspot.com
  • HeritageFossils' Blog
  • Fossilefinder's Blog
  • Fossilefinder's Blog
  • Emily's MotE Adventure
  • farfarawy's Blog
  • Microfossil Mania!
  • A Novice Geologist
  • Southern Comfort
  • Eli's Blog
  • andreas' Blog
  • Recent Collecting Trips
  • The Crimson Creek
  • Stocksdale's Blog
  • andreas' Blog test
  • fossilman7's Blog
  • Hey Everyone :P
  • fossil maniac's Blog
  • Piranha Blog
  • xonenine's blog
  • xonenine's Blog
  • Fossil collecting and SAFETY
  • Detrius
  • pangeaman's Blog
  • pangeaman's Blog
  • pangeaman's Blog
  • Jocky's Blog
  • Jocky's Blog
  • Kehbe's Kwips
  • RomanK's Blog
  • Prehistoric Planet Trilogy
  • mikeymig's Blog
  • Western NY Explorer's Blog
  • Regg Cato's Blog
  • VisionXray23's Blog
  • Carcharodontosaurus' Blog
  • What is the largest dragonfly fossil? What are the top contenders?
  • Hihimanu Hale
  • Test Blog
  • jsnrice's blog
  • Lise MacFadden's Poetry Blog
  • BluffCountryFossils Adventure Blog
  • meadow's Blog
  • Makeing The Unlikley Happen
  • KansasFossilHunter's Blog
  • DarrenElliot's Blog
  • jesus' Blog
  • A Mesozoic Mosaic
  • Dinosaur comic
  • Zookeeperfossils
  • Cameronballislife31's Blog
  • My Blog
  • TomKoss' Blog
  • A guide to calcanea and astragali
  • Group Blog Test
  • Paleo Rantings of a Blockhead
  • Dead Dino is Art
  • The Amber Blog
  • TyrannosaurusRex's Facts
  • PaleoWilliam's Blog
  • The Paleo-Tourist
  • The Community Post
  • Lyndon D Agate Johnson's Blog
  • BRobinson7's Blog
  • Eastern NC Trip Reports
  • Toofuntahh's Blog
  • Pterodactyl's Blog
  • A Beginner's Foray into Fossiling
  • Micropaleontology blog
  • Pondering on Dinosaurs
  • Fossil Preparation Blog
  • On Dinosaurs and Media
  • cheney416's fossil story
  • jpc
  • Red-Headed Red-Neck Rock-Hound w/ My Trusty HellHound Cerberus
  • Red Headed
  • Paleo-Profiles

Calendars

  • Calendar

Categories

  • Annelids
  • Arthropods
    • Crustaceans
    • Insects
    • Trilobites
    • Other Arthropods
  • Brachiopods
  • Cnidarians (Corals, Jellyfish, Conulariids )
    • Corals
    • Jellyfish, Conulariids, etc.
  • Echinoderms
    • Crinoids & Blastoids
    • Echinoids
    • Other Echinoderms
    • Starfish and Brittlestars
  • Forams
  • Graptolites
  • Molluscs
    • Bivalves
    • Cephalopods (Ammonites, Belemnites, Nautiloids)
    • Gastropods
    • Other Molluscs
  • Sponges
  • Bryozoans
  • Other Invertebrates
  • Ichnofossils
  • Plants
  • Chordata
    • Amphibians & Reptiles
    • Birds
    • Dinosaurs
    • Bony Fishes
    • Mammals
    • Sharks & Rays
    • Other Chordates
  • *Pseudofossils ( Inorganic objects , markings, or impressions that resemble fossils.)

Found 5 results

  1. In this second entry I would like to show well-preserved specimens of two ostracodes: the very long-ranging taxon Amphissites centronotus (Ulrich and Bassler, 1906), and the Permian taxon Cornigella parva Kellett, 1933. The former belongs in the family Amphissitidae, while the latter is placed in the family Drepanellidae. This specimen is a relatively late instar, but not fully mature, as final instar specimens average about 50% larger. The species is very easy to recognize, the very large and prominent central node being quite distinctive. Additionally, there are two strong ventral flanges, the inner flange curving upward to the anterior cardinal angle. There is a fairly strong dorsal ridge, the ends curving abruptly downward to form anterior and posterior ridges, the former being the longer of the two. The flanges and ridges are considerably weaker on early instars, but the prominent central node is still unmistakable. So far as I am aware, this taxon occurs throughout the Pennsylvanian (and perhaps earlier), and disappears by mid-Permian time, a range in excess of 100 Ma. It has been assumed that this species was a free-swimming benthic form, as the prominent flanges would not be well-suited to an infaunal mode of life. Betty Kellett described two species of the genus Cornigella from the Fort Riley Limestone of the Chase Group, higher in the Permian section of Kansas: Cornigella parva Kellett 1933, and Cornigella binoda Kellett 1933. They differed in the number of lateral nodes, the former species having a larger number of nodes, while in the latter species only the two prominent dorsal nodes were present. However, Kellett noted that her specimens showed considerable variation, which she attributed to poor preservation and diagenetic crushing. She went so far as to suggest that the two described taxa might actually be the same. Looking at Florena specimens, which are well-preserved complete carapaces, I would agree with her suggestion. The lateral nodes exhibit varying degrees of development; although the two dorsal nodes are always strongly developed, the ventral and anterior nodes may be considerably weaker. The specimen shown here is very well-preserved, and the full (?) complement of lateral nodes is clearly represented. (Note that, since we are looking at a complete carapace, the posterior dorsal node of the right valve is also obvious, as is a hint of the anterior dorsal node.) This specimen is also of interest, in that it shows a lot of the surface sculpturing, not too obvious on other specimens. I have chosen the name C. parva for this taxon, as Kellett's description appears first on the page, and should thus have priority. I have not seen the description or illustrations of the generotype Cornigella minuta Warthin, 1930, which was described as having eight "prominent spines", one projecting well above the hinge line. Type specimens were from the Pennsylvanian Wetumka Formation of Oklahoma. I would follow Kellett's judgement in deciding that the Permian taxon was not conspecific with that of Warthin. I had hoped to illustrate a perfect carapace of Ectodemites pinguis (Ulrich and Bassler, 1906) from the Florena, which I had temporarily stored in a small black plastic tray (the lid of a micromount box) on my desktop. Unfortunately, when I went to retrieve it for photography, it had simply disappeared -- even though I thought it to be well covered! Now it's fodder for the vacuum cleaner, one of the hazards of microfossil collecting................!
  2. In picking out my sample of microfossils from the Middle Pliocene Coralline Crag Formation, Suffolk, England, I noted a few fragments of what appeared to be a species of the ostracode genus Pterygocythereis, a particularly spiny-looking genus of the family Trachyleberididae. I assumed it to be Pterygocythereis jonesi (Baird, 1850), the common species of the North Sea. As luck would have it, while finishing the picking of the last bit of the sample, up popped a complete valve, in almost perfect condition. To my surprise, it turned out not to be the common North Sea species; rather, it is Pterygocythereis siveteri Athersuch, 1972. The image does not do it justice, as even with image stacking software, the great length of the alae and the 3-D spininess are not very apparent. (Published dorsal views of the complete carapace are quite impressive!) Further cleaning of the specimen should greatly improve its appearance. In the standard book on the recent Ostracoda of Great Britain, we find the following: "British records of P. siveteri are sub-Recent, and there are, as yet, no live records outside the Mediterranean." (Athersuch, Horne and Whittaker 1989: 146) Presence of this species thus provides further evidence that the Middle Pliocene sea around southern Great Britain was warmer than it is now, and that the ostracode fauna was essentially Lusitanian, characteristic of the modern Mediterranean Sea and of the Atlantic Ocean off the northwest coast of Africa. The genus Pterygocythereis today is commonly encountered in the sublittoral zone, down to a depth of about 200 meters. Faunal studies of the Coralline Crag have suggested that it was deposited in a high energy environment with a maximum depth of about 20 meters, which seems to fit. However, this species is rather rare in the Coralline Crag, suggesting that it may not have been a member of the original, local biocoenosis. Athersuch, J., D. J. Horne, and J. E. Whittaker, 1989, Marine and Brackish Water Ostracods, The Linnaean Society of London.
  3. I have about 8 acres of coastal estuary in northern Nova Scotia, and decided to take a look at the estuary sediments to see if I could find any fossils. Yes, they are there! Microfossils and lots of other life including ostracoda. Using my hand lens I could see them very well. Will invest at sometime in a microscope and maybe I will see even more. Hand lens for scale for foraminifera and ostracod scale is in millimeters.
  4. Lit.: World heritage nomination: Chengjiang Fossil Site (40MB, excellent overview with many pictures)
  5. I have always enjoyed looking at ostracodes of the family Trachyleberididae, for their varied and complex structures, and interesting ornamentation. The family seemingly first appeared in the Middle Jurassic, became abundant during the Cretaceous, and remains abundant in the seas of today. About a month ago, in an exchange of microfossil material with an Italian friend, I received a sample of material from the Coralline Crag of southeastern England, a well-known and extensively studied Middle Pliocene (Zanclean) marine deposit of cross-bedded sands. The deposit averages about 12 meters in thickness, varies from weakly to more strongly consolidated, and is highly fossiliferous. The name comes from an abundance of bryozoans, which early scholars mistakenly thought were corals. Ostracodes and foraminifera are both abundant. Faunal studies have suggested that the sea was a bit warmer when this formation was laid down, perhaps more closely resembling the Mediterranean Sea, or the Atlantic Ocean off the northwest coast of Africa. Hence the Coralline Crag contains many species that do not much resemble those found in the marine littoral deposits of modern-day England. I have recovered quite a few species of both forams and ostracodes from my sample, and am just beginning the identification process. The species I want to show off in this entry is the first I have identified, chosen to be investigated first because it is both common and showy. The taxon is correctly known as Cletocythereis jonesi Wood et al., although it was previously known by various other names through misidentification. It is a typical trachyleberidid, although with much coarser surface sculpture than most. The valves are subquadrate and rather thick, with an amphidont hinge. The surface is coarsely reticulate, with a strong sub-central tubercle, and dorsal and ventral ridges. The anterior margin is also reticulate, divided into elongate, transverse cells. The ventral ridge terminates posteriorly in a complex loop. The eye tubercle, just below the anterior dorsal margin, is large and shiny. Here is an interior view of the same right valve, unfortunately obscured by residual matrix. The ventral margin exhibits a strong concavity; the posterior dorsal corner is not broken, contrary to appearances, and is a close match to images of the type specimens. The hinge of the right valve has a strong, round anterior tooth. The posterior tooth is weaker, and the middle element is of the smooth groove-and-bar type; the right valve has the grooved element, and there is a corresponding thin bar in the left valve. This dorsal view shows the thickened central part of the carapace, due to the dorsal and ventral ridges, and the relatively flat anterior and posterior margins. Personally, I think this is a really handsome microfossil -- considering that its largest dimension is only about 1 millimeter in length! In future entries in this blog I hope to illustrate a few other ostracodes and forams from this interesting formation, if I am able to make more identifications. Fortunately, I have access to a good research library! Two interesting references are: Wilkinson, I. P., 1980, "Coralline Crag Ostracoda and their environmental and stratigraphical significance," Proceedings of the Geologists' Association 91:291-306. Wood, A. M., R. C. Whatley, C. A. Maybury, and I. P. Wilkinson, 1992, "Three new species of cytheracean Ostracoda from the Coralline Crag at Orford, Suffolk," Journal of Micropaleontology 11:211-220.
×