Marshalltown Formation

The Marshalltown Formation is a Late Cretaceous (Campanian)-aged geologic formation in New Jersey and Delaware, US. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation. It contains the most extensive Campanian-aged dinosaur fauna from New Jersey and Delaware.Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607.

The famous Ellisdale Fossil Site, a konzentrat-lagerstätten which contains one of the most diverse Cretaceous vertebrate assemblages (likely rapidly buried in a massive flood event) known from eastern North America/former Appalachia, is an exposure of this formation.

The Marshalltown Formation stretches across southern New Jersey to northern Delaware, and is largely composed of marine sediments deposited off the eastern shore of Appalachia, although the Ellisdale site represents a fluvio-deltaic or tidal-estuarine environment reminiscent of the modern Albemarle Sound, and thus has more of a terrestrial influence.

Vertebrate paleobiota Based on the Paleobiology Database:

Cartilaginous fish Cartilaginous fish of the Marshalltown FormationGenusSpeciesMemberLocationMaterialNotesImages

Bony fish Based on: Bony fish of the Marshalltown FormationGenusSpeciesMemberLocationMaterialNotesImagesAcipenserA. sp.Ellisdale SiteA sturgeon.AnomoeodusA. phaseolusEllisdale Site, St. GeorgesA pycnodont.AtractosteusA. sp.Ellisdale SiteA gar.CyclurusC. cf. fragosusEllisdale SiteAn amiid related to bowfins.cf. CylindracanthusC. sp.St. George'sA fish of uncertain affinities.EnchodusE. feroxEllisdale Site, St. GeorgesAn enchodontid aulopiform.E. sp.St. Georgescf. LepisosteusL. sp.St. GeorgesA gar.ParalbulaP. caseiEllisdale Site, St. GeorgesA phyllodontid elopomorph.cf. "Platacodon"P. sp.Ellisdale SiteA sciaenid-like fish.StephanodusS. sp.St. GeorgesA pycnodont.XiphactinusX. audaxEllisdale SiteAn ichthyodectid.X. sp.St. Georges

Amphibians Amphibians of the Marshalltown FormationGenusSpeciesMemberLocationMaterialNotesImagesAlbanerpetontidae indet.Ellisdale SiteAn albanerpetontid.Alytidae indet.An alytid frog.cf. HabrosaurusH. sp.A sirenid salamander.ParrisiaP. neocesariensisA batrachosauroidid salamander. Type locality of genus and species.Pelobatidae indet.A relative of European spadefoot toads.cf. ProamphiumaP. sp.A sirenid salamander.cf. ScotiophryneS. sp.A frog of uncertain affinities.cf. TheatoniusT. sp.A frog of uncertain affinities.

Reptiles

Dinosaurs Based on Brownstein (2018): Dinosaurs of the Marshalltown FormationGenusSpeciesMemberLocationMaterialNotesImages"Coelosaurus"C. antiquusAn ornithomimosaur.Coelurosauria indet.Ellisdale SiteA coelurosaur theropod of uncertain affinities.Dromaeosauridae indet.A dromaeosaurid theropod of uncertain affinities.DryptosaurusD. sp.A tyrannosauroid theropod. Specimens from this formation might belong to Appalachiosaurus instead.Hadrosauridae indet.A hadrosaurid ornithopod.?Hadrosauroidea indet.A hadrosauroid ornithopod.HadrosaurusH. foulkiiA hadrosaurid ornithopod.?H. sp.HypsibemaH. crassicaudaA hadrosauroid ornithopod.Nodosauridae indet.A nodosaurid ankyosaur.Ornithopoda indet.An ornithopod of uncertain affinities.

Crocodilians Crocodilians of the Marshalltown FormationGenusSpeciesMemberLocationMaterialNotesImagescf. "Allognathosuchus""A". sp.Ellisdale SiteAn alligatorid.cf. BrachychampsaB. sp.Ellisdale SiteAn alligatorid.DeinosuchusD. rugosusEllisdale SiteAn alligatoroid, one of the largest known crocodilians. Remains of both juveniles and adults known."Diplocynodon""D". sp.Ellisdale SiteAn alligatorid."Leidyosuchus""L". sp.Cambridge Crossing Executive ParkAn alligatorid.

Turtles Turtles of the Marshalltown FormationGenusSpeciesMemberLocationMaterialNotesImagesAdocusA. beatusEllisdale SiteAn adocid.ChedighaiiC. barberiEllisdale SiteA bothremydid side-necked turtle.CorsochelysC. sp.Ellisdale SiteA dermochelyid sea turtle.Trionychidae indet.Ellisdale Site, St. GeorgesA softshell turtle of uncertain affinities.

Plesiosaurs Plesiosaurs of the Marshalltown FormationGenusSpeciesMemberLocationMaterialNotesImages"Elasmosaurus""E." orientalisSwedesboroTwo back vertebraeAn elasmosaurid, species name is a nomen dubium due to fragmentary nature.

Squamates Squamates of the Marshalltown FormationGenusSpeciesMemberLocationMaterialNotesImagesClidastesC. iguanavusSwedesboroA mosasaurine mosasaur. Type locality of species.cf. C. sp.St. Georges?ContogenysC. sp.Ellisdale SiteA globaurid lizard.cf. GlobidensG. sp.St. GeorgesA globidensine mosasaur.Glyptosaurinae indet.Ellisdale SiteAn anguid lizard.cf. HalisaurusH. sp.Ellisdale SiteA halisaurine mosasaur.HaptosphenusH. sp.Ellisdale SiteA chamopsid lizard.cf. OdaxosaurusO. sp.Ellisdale SiteAn anguid lizard.cf. MachaerosaurusM. sp.Ellisdale SiteAn anguid lizard.PrototeiusP. stageriEllisdale SiteA chamopsid lizard. Type locality of genus and species.

Choristodera Choristoderes of the Marshalltown FormationGenusSpeciesMemberLocationMaterialNotesImagesNeochoristodera indet.Ellisdale Site1 vertebraA neochoristodere, one of the very few records of this group from eastern North America.

Mammals Based on Grandstaff et al (1992): Mammals of the Marshalltown FormationGenusSpeciesMemberLocationMaterialNotesImagesCimolodontidae indet.Ellisdale SiteA cimolodontid multituberculate.CimolomysC. cf. clarkiA cimolomyid multiberculate.cf. DidelphodonD. sp.A stagodontid metatherian.ProtalphadonP. lulliA metatherian.

Marshalltown Formation

Bron en licentie