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| | Fossil Record of the Cheliceramorpha |
 | | Although it lacks the chelae, or claws, which give the group its name, it does show the same pattern of tagmosis (clustering and specialization of segments) that characterizes all chelicerates. | | | The oldest certain chelicerate currently known is Sanctacaris from the Middle Cambrian Burgess Shale of British Columbia. |
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http://www.ucmp.berkeley.edu/arthropoda/chelicerata/chelicerafr.html
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| | Sanctacaris |
| | There are 11 body segments each with a pair of walking legs and gills. | | | Unlike most other Burgess forms, Sanctacaris is not present in Walcott's 1909 quarry and was discovered at a different level by Desmond Collins in 1980-1981. | | | Sanctacaris appears to be a primitive chelicerate arthropod. |
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http://www.theezine.net/s/sanctacaris.html
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| | Palaeos Invertebrates: Arthropoda: Arthropod Phylogeny - problems in interpreting the Arthropod family tree |
| | For example, Sarotrocercus, said at different times to be close to Limulus and a eurypterid, then to Yohoia and Sanctacaris, and most recently to Molaria and Leonchoilia, bears little resemblance to any of these very different animals and is in fact one of the most primitive arthropods yet discovered. | | | Single characters...can be misleading and, not surprisingly, are often less informative than complexes, which arthropods display in profusion and whose changes during the course of evolution can sometimes be followed in detail." |
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http://www.palaeos.com/Invertebrates/Arthropods/phylogeny.html
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| | Re: finding a good DME in Seattle |
| | A good DME...I was "given one" after my sleep study at Overlake :^) I think the key is asking for what you want, and being assertive. | | | Re: finding a good DME in Seattle sanctacaris 17:07 7/21/05 ( | | | To post a new topic go to the Sleep Apnea Forum Homepage. |
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http://www.sleepnet.com/apnea128/messages/149.html
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| | Trilobite Origins |
| | The bilobate exopod appears to be very general within Arachnata (e.g., present in Sanctacaris). | | | Some detailed characters present in these taxa, such as the division of the exopod into proximal and distal lobes (the former bearing lamellar setae and the latter fringed with bristles) and hinging of the exopod along the basis, are more generally distributed, also being present in xandarellids and other Cambrian forms, such as Emeraldella. |
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http://www.peripatus.gen.nz/Taxa/Arthropoda/Trilobita/TriOri.html
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| | Is Sanctacaris an arthropod? |
| | Based on the available evidence, is Sanctacaris part of the arthropod lineage? | | | Read how others have recognized the Understanding Evolution website. | | | Then compare what you see to the arthropod checklist below. |
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http://evolution.berkeley.edu/evolibrary/article/0_0_0/cambrian_04
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| | :: Purpose in Evolution :: |
| | The soft-bodied organisms preserved there, like the Sanctacaris pictured above, is from the middle Cambrian Period, some 500 million years ago when there was an explosion of new forms of animal life on Earth. | | | The fossils of the Burgess Shale quarry are a window on our past. | | | The Sanctacaris is from an early group of arthropods that gave rise to sea urchins, horseshoe crabs, and spiders. |
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http://www.templeton.org/humble04/participants.html
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| | ConceptArt.org Forums - Useful links for COWies |
| | The list is however incomplete, there are a few Cambrian organisms not listed there (like Sanctacaris, for example. |
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http://www.conceptart.org/forums/archive/index.php?t-46874.html
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| | Chelicerata -- Facts, Info, and Encyclopedia article |
| | (Click link for more info and facts about Sanctacaris) Sanctacaris, and perhaps the aglaspids, may also belong here. | | | These are extinct forms found in (From 544 million to about 500 million years ago; marine invertebrates) Cambrian rocks. |
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http://www.absoluteastronomy.com/encyclopedia/c/ch/chelicerata.htm
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| | Taphonomy |
| | This section is part of a Fossil Lagerstätten web site which has been built up as a result of the efforts of the 2002-3 MSc Palaeobiology class in the Department of Earth Sciences at University of Bristol, as part of a course in Scientific Communication. | | | Note the fine preservation of the head appendages and the clear delineation of segments along the body. | | | On the right is a reconstruction of Sanctacaris as it appeared in life. |
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http://palaeo.gly.bris.ac.uk/palaeofiles/lagerstatten/Burgess/taphonomy.html
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| | GEOL 331 Lectures 29-31: Arthropoda |
| | An early representative: Sanctacaris of the Burgess shale. | | | Breath by book gills (book lungs in the terrestrial arachnids, and even trachaea in some specialized small-bodied arachnids) |
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http://www.geol.umd.edu/~tholtz/G331/lectures/331arthr.html
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| | Errors in Darwin's Dangerous Idea |
| | Walcott himself did not "literally dissect" the fossils. | | | up 4-6 lines: the spelling should be Naraoia, Sanctacaris, and Leanchoilia. |
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http://ase.tufts.edu/cogstud/papers/errors.html
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| | The Cambrian explosion - Burgess Shale type faunas |
| | Burgess Shale type faunas have now been discovered at over 30 other localities in Greenland, China, Poland, Australia, and from rocks ranging in age through Lower and Middle Cambrian. | | | Compaction took place, but fine mud particles infilled every space in and around the organism, preserving a degree of three-dimensionality and allowing the Cambridge team to disect down through the fossils to reveal hidden structures. | | | A Burgess Shale fossil of the arthropod Sanctacaris. |
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http://palaeo.gly.bris.ac.uk/Palaeofiles/Cambrian/fossils/burgess/burgess.html
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| | Timeline Canada |
| | Specimens include: Pikaia (a chordate, ancestor of fish, reptiles, and mammals), Odontogriphus, Amiskwia, Ottoia (a Priapulid worm), Wiwaxia (a Polychaete worm or mollusk), Burgessochaeta (an annelid worm), Opabinia, Sanctacaris (arthropod, forerunner of spiders and scorpions), Canadaspis (arthropod, early crustacean), Aysheaia (possible arthropod), Eldonia, Hyolith, Brachiopods, Dinomischus, Anomalocaris, Sponges and Trilobites. | | | In 1989 Stephen Jay Gould authored "Wonderful Life: The Burgess Shale and the Nature of History." In 1998 Simon Conway Morris authored "The Crucible of Creation: The Burgess Shale and the Rise of Animals." |
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http://timelines.ws/countries/CANADA.HTML
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| | National Museum of Natural History - Paleobiology |
| | Just below center stage, Opabinia's trunk-like snout has caught Burgessochaeta, a bristle worm relative of Canadia (not shown.) There, to its left, Hallucigenia and Wiwaxia scurry along just in front of a very large Sanctacaris. | | | At center left, Aysheaia dines on the sponge Vauxia while at lower left, Microdicyton nibbles away on a companion sponge. | | | Then, just to its left, Pikaia swims above the substrate showing its flattened tail. |
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http://www.nmnh.si.edu/paleo/shale/pamsci.htm
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| | Burgess Shale Formation |
| | + a soft-bodied and lightly scleritzed fauna on Mt. Stephen, including: Alalcomenaeus, Branchiocaris, Canadaspis, Naroia, Plenocaris, Sanctacaris uncata, Leptomitus, Wiwaxia, and Xanioascus) |
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http://www.westernta.com/Formations/Burgess.htm
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| | Burgess Shale trilobites |
| | Waptia (17), Helmetia (13), Sanctacaris (18), Tegopelte (15), Naraoia (16), Leanchoilia (10), Canadaspis (12), |
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http://www.trilobites.info/Burgess.htm
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