| Hauffiosaurus | |
|---|---|
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| Entire skeleton in ventral view ofH. zanoni. | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Superorder: | †Sauropterygia |
| Order: | †Plesiosauria |
| Family: | †Pliosauridae |
| Genus: | †Hauffiosaurus O'Keefe,2001 |
| Species | |
| Synonyms | |
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Hauffiosaurus is anextinctgenus ofEarly Jurassic (early Toarcian stage)pliosauridplesiosaur known fromHolzmaden ofGermany and fromYorkshire of theUnited Kingdom. It was first named by Frank Robin O’Keefe in2001 and thetype species isHauffiosaurus zanoni.[1] In 2011, two additional species were assigned to this genus:H. longirostris andH. tomistomimus.[2]
Theholotype specimen ofHauffiosaurus, housed in the Hauff Museum, is an almost complete and articulatedskeleton, found from the Posidonien-Schiefer, dating to earlyToarcian stage of theEarly Jurassic. Theholotype specimen preserved in a single block of the original matrix, exposed inventral view. The body outline visible around the specimen is an artifact of preparation, not preservation; no remains of soft tissue were preserved.[1] The skeleton was discovered during the early 19th Century,[3] in beds of the famous Posidonien-Schieferlagerstätte atHolzmaden, Baden-Württemberg, in southeastern Germany. However, it was not recognized as a validtaxon, and no thorough description of thefossil was made until 2001. The specific name honours Robert Thomas Zanon, who was the first to recognise the specimen as a separate genus.[1]
Hauffiosaurus zanoni is a plesiosaur of medium size, measuring 3.4 metres (11 ft). The skull measures about 430 millimetres (1 ft) along the midline. The holotype is an adult individual, but incomplete fusion of thepectoral andpelvic girdle indicate it is not an old adult. The specimen is displayed at theUrwelt-Museum Hauff, Holzmaden. The exactphylogenetic position ofHauffiosaurus within the Plesiosauria has yet to be resolved, though Vincent (2011) states that it may "reasonably be placed within the Pliosauroidea".[4]
A second species,H. tomistomimus, was named by Roger B. J. Benson, Hilary F. Ketchum, Leslie F. Noè and Marcela Gómez-Pérez in2011. It is known from theholotype and only specimen, MMUM LL 8004, an almost complete, three-dimensionally preservedand and articulatedskeleton, found from theHildoceras bifrons Zone (181.2–180.7Ma) of theAlum Shale Member,Whitby Mudstone Formation, dating to earlyToarcian stage. This skeleton was discovered inYorkshire,UK. The holotype ofH. tomistomimus measures 4.83 metres (15.8 ft) long.[4]
Bensonet al. (2011) also reassignedMacroplata longirostris (originallyPlesiosaurus longirostris[5]) toHauffiosaurus. The holotype and only specimen ofH. longirostris, MCZ 1033, found from theHarpoceras serpentinum Zone (182.7–181.2 Ma) of theJet Rock Member, Whitby Mudstone Formation, early Toarcian of Yorkshire, England.[2] The individual to which this specimen belongs is estimated to have measured approximately 4.83 m (15.8 ft) in total body length.[6]
Few Early Jurassic plesiosaurians have the sort of long, thin snout present inHauffiosaurus, a shape usually considered to indicate a diet offish (ichthyophagy). The teeth are slender and elongated and possess fine longitudinal ridges. This sort oftooth, coupled with the longrostrum seen in this genus is effective in piercing soft prey.[7]
Smith & Dyke, 2008 were the first who foundHauffiosaurus to be basal pliosauroid. Benson, Ketchum, Noè and Gómez-Pérez who assigned two additional species to this genus, confirmed the affinity of this taxon toPliosauroidea using cladistic analysis which was based on Ketchum & Benson's (2010) analysis.Cladogram after Bensonet al., 2011:[2]
| Plesiosauria |
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With the description ofMarmornectes in 2011, Ketchum & Benson suggested for the first time that many basal plesiosaurs and pliosauroids are members ofPliosauridae andRhomaleosauridae. Both Rhomaleosauridae and Pliosauridae were found to be monophyletic, and the relations betweenHauffiosaurus's species remained the same. The cladogram below follows Ketchum & Benson, 2011.[8]
| Pliosauroidea |
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