The Lueders Formation is a geologic formation in Texas. It is the top formation of the Albany Group and preserves fossils dating back to the Permian period.
Description Paleogeography At the time of deposition, a broad sea connected to the Panthalassic Ocean covered much of the central United States, including Texas. The Lueders Formation would have been located in the northern tropics or subtropics. Climatically, after the retreat of an early Artinskian glacial maximum, the deserts of the North American craton experienced fluctuation and growth during this time period, and the associated aridity decrease impacted seabed deposition in localities across the basin.
Depositional environment The Lueders Formation represents a deltaic environment, with terrestrial sediments being deposited onto the muddy bottom of a shallow estuary by shifting freshwater streams. In the Maybelle Member, the dolomite likely represents marine deposits, preserving marine sharks and fish, whereas darker terrestrial sediments and freshwater shale deposits contain remains of land animals and freshwater fish respectively.
Fossil content Amphibians Amphibians reported from the Lueders Formation Genus Species Presence Material Notes ImagesCrossotelosC. annulatusMaybelle Member.Multiple specimens.A nectridean.DiplocaulusD. magnicornisMaybelle Member.Multiple specimens.A nectridean.EryopsE. megacephalusMaybelle Member.Limb & skull elements.An eryopid.TrimerorhachisT. sp.Maybelle Member.Limb & skull elements.A dvinosaur.
Fish Acanthodians Acanthodians reported from the Lueders Formation Genus Species Presence Material Notes ImagesAcanthodesA. sp.Maybelle Member.A fin spine.An acanthodiform, known from freshwater deposits.
Bony fish Bony fish reported from the Lueders Formation Genus Species Presence Material Notes Images"Acrolepis"Maybelle Member.Scales.A palaeonisciform.GnathorhizaG. serrataMaybelle Member.Jaw elements & near-complete specimen.A lungfish from freshwater deposits.LawniaL. cf. L. taylorensisMaybelle Member.Remains of millions of individuals.A palaeonisciform originally reported as 'Lawnia-like', now thought to represent the genus itself.LuederiaL. kempiMaybelle Member.A braincase & 2 large cleithra.A marine palaeonisciform.?Platysomus?P. palmarisMaybelle Member.Partial bodies & numerous scales.A marine (?) palaeonisciform.SagenodusMaybelle Member.Upper tooth plate (UCLA VP 431).A lungfish.SchaefferichthysS. leudersensisMaybelle Member.Incomplete specimen (USNM 23109).A freshwater palaeonisciform.?Spermatodus?S. pustulosusMaybelle Member.Multiple specimens.A coelacanth.
Cartilaginous fish Cartilaginous fish reported from the Lueders Formation Genus Species Presence Material Notes ImagesAcrodus?A. olsoniTeeth.A hybodont.?A. sweetlacruzensisTeeth.A hybodont.BarbclaborniaB. luedersensisNumerous teeth.A giant freshwater xenacanth.CtenacanthusC. cf. C. amblyxiphiasMaybelle Member.Fin spines.A ctenacanth found in the marine dolomite.JanassaJ. sp.Maybelle Member.Isolated teeth.A petalodont found in the marine dolomite.OrthacanthusO. platypternusTeeth.A freshwater xenacanth.O. texensisTeeth.A freshwater xenacanth.PolyacrodusP. wichitaensisTeeth.A hybodont.P. zidekiTeeth.A hybodont.Xenacanthus?X. slaughteriTeeth.A freshwater xenacanth.X. sp.Maybelle Member.A tooth.A freshwater xenacanth.
Synapsids Synapsids reported from the Lueders Formation Genus Species Presence Material Notes ImagesDimetrodonD. sp.Maybelle Member.Neural spine & bone fragments.A sphenacodontid.
Invertebrates Arthropods Arthropods reported from the Lueders Formation Genus Species Presence Material Notes ImagesOstracoda indet.IndeterminateWSU 1445.A fragmentary ostracod.PanduralimulusP. babcockiMaybelle Member.Multiple specimens.A horseshoe crab.
Bivalves Bivalves reported from the Lueders Formation Genus Species Presence Material Notes ImagesMyalinellaM. sp.Valves (WSU 1407).A myalinid.Pinnidae indet.IndeterminateShell.An unknown pen shell.
Bryozoans Bryozoans reported from the Lueders Formation Genus Species Presence Material Notes ImagesBryozoa indet.IndeterminateWSU 1430.A fragmentary bryozoan.
Cephalopods Cephalopods reported from the Lueders Formation Genus Species Presence Material Notes ImagesKoninckiocerasK. bibbiInternal mold.A nautiloid.MetacocerasM. sp.Shell (WSU 1437).A nautiloid.MichelinocerasM. sp.Phragmocone (WSU 1406).A orthocerid.MillkoninckiocerasM. sp.Shell (WSU 1442).A nautiloid.Perrinitidae indet.Indeterminate3 specimens.An ammonite.Stenopocerascf. S. whiteiPhragmocone.A nautiloid.
Echinoderms Echinoderms reported from the Lueders Formation Genus Species Presence Material Notes ImagesCrinoidea indet.IndeterminateColumnal (WSU1405A).A fragmentary crinoid.
Plants Plants reported from the Lueders Formation Genus Species Presence Material Notes ImagesTinsleyaT. texanaMaybelle Member.Numerous specimens.A pteridosperm.ZeilleropterisZ. wattiiLeaves.A gigantopterid.
See also
List of fossiliferous stratigraphic units in Texas Paleontology in Texas
References