Wednesday, November 30, 2011

Sam Noble Oklahoma Museum of Natural History: First Entry for Recent Inverts!

   Welcome to the new blog of the Department of Recent Invertebrates at the Sam Noble Oklahoma Museum of Natural History (SNOMNH), in Norman, Oklahoma. The SNOMNH is a state-repository for artifacts and history of Oklahoma, and is part of the University of Oklahoma.
   The museum itself has several departments, all of which are listed on the museum website. These departments encompass several branches of both human history (Ethnology, Archaeology, Languages) and natural history (Vertebrate Paleontology, Invertebrate Paleontology, Mammalogy, Herpetology, etc.), mostly focused on Oklahoma but including material from all over the world. Though all of these branches and topics are important, we are going to focus on one natural history grouping that is both the most numerous and also the most interesting (yes, there is some bias here): invertebrates.
   Invertebrates comprise up to 97% of all known animal life; far more than mammals, birds, reptiles and amphibians combined. All invertebrates lack a back-bone (in-meaning missing, vertebrate- vertebrae, part of the backbone), have multiple cells, and those cells are eukaryotic (meaning they have a nucleus with a membrane and other membrane-bound organelles: this excludes things like viruses or bacteria). A good summary of characters of invertebrates is provided by Wikipedia here.
   Our Recent Invertebrates collection includes invertebrates that are not fossilized. Our department of Invertebrate Paleontology deals with invertebrates of the very distant past, including taxa as the super-diverse Trilobites that evolved in the Precambrian period, and had at least 20,000 species at their prime. Now they are extinct, but in modern times we have another lineage of megadiverse invertebrates: the Insecta, or insects.
   Insects are a lineage of Arthropoda, the largest phylum of Invertebrates. Arthropods are united by having a hard exoskeleton with jointed appendages (arthro- jointed, poda- foot), and include other sub-phyla such as Crustaceans (crabs, shrimp), and the sub-phyla Trilobita (trilobites) mentioned earlier. Part of what makes arthropods so successful is their hard exosceleton, as well as their ability to exploit several different habitats during different life-stages of development. Current insects are dominantly terrestrial organisms (meaning they live out of water, on the land), and are one of the first major arthropod lineages (and animal lineages) to make the transition onto land from the primarily ocean-based life of Earth's early history. However, many insects still have some form of their development tied to water, especially the older lineages of insects (Dragonflies, Mayflies, etc.), and several lineages have returned back to water to re-exploit resources of the habitat (e.g. aquatic beetles, aquatic Heteropterans such as Water-striders). Still, several other arthropod groups are still primarily aquatic (living in water) and mostly marine (living in the ocean), especially the Crustaceans. In fact, there is only group of Crustaceans that live on the land: the Armadillidiidae, or Pill-bugs. In Oklahoma you can see these little crustaceans wandering around moist environments during the spring, summer, and fall, usually in the early mornings, looking for food.
   Because Oklahoma is primarily a terrestrial environment (though we do have several unique freshwater environments, including streams, lakes and rivers), our invertebrates collection at the SNOMNH is mostly comprised of terrestrial insects. However, we do have several very good collections of freshwater crayfish (crustaceans), freshwater mollusks (snails, clams, oysters), and other invertebrate taxa unique to Oklahoma. In addition, we have several specimens of invertebrates from all over the world to diversify our collection, including representatives from marine environments like corals, jelly-fish, crabs, and more obscure marine invertebrate taxa (polychaete worms, etc.). We also have one of the best aquatic beetle collections in the world, of the group Byrrhoidea (which includes the Long-toed beetles, Water-pennies, and riffle-beetles), due to the extensive work of former curator Dr. Harley Brown. Dr. Brown did extensive field work in Oklahoma, the Southwest United States and Mexico, and Central and South America.
   Each week we will be posting stories that highlight one group of invertebrates from our collection. Further, we will be posting information about major events and finds in our collection as we catalog and database our material. So please come back and see what's new and to learn more about our specimens and collection here at the SNOMNH!