The Posongchong Formation is an early Devonian formation from China. It preserves a wide range of plant and fish fossils, many being only known from this formation.
Paleobiota
Plants
PlantsGenusSpeciesHigher taxonNotesImagesAdoketophytonA. subverticillatum, A. parvulum, A. pingyipuensisLycophyta?Formerly placed within ZosterophyllumAmplectosporangiumA. jiangyouense, A. unilaterale, A. unilaterale forma minorincertae sedisA. unilaterale was formerly placed within OricillaBaragwanathiaB. sp.DrepanophycalesOnly known from leafy stems, cannot be placed in a speciesCatenalisC. digitataTracheophyta incertae sedisIntermediate between algae and vascular plantsCelathecaC. beckiiLyginopteridales?One of the earliest known seed plantsCervicornusC. wenshanensisSphenopsida?Sporangia unknown, may be synonymous with EstinnophytonDemersathecaD. contiguaZosterophyllsOnly known from fertile axesDibracophytonD. acrovatumBarinophytopsida incertae sedisRelatively unusual with dichotomous branching "leaves"DiscalisD. longistipaZosterophyllalesBears spines on its main axes, somewhat resembles SawdoniaDistichophytumD. sp.ZosterophyllalesOnly known from a fragmentary specimenEstinnophytonE. yunnanenseSphenopsida?Possibly a stem-sphenopsidEophyllophytonE. bellumEophyllophytopsida (Euphyllophytes)Oldest plant with megaphyllous leavesGuangnaniaG. cuneataZosterophyllopsida?Unclear whether it truly is a zosterophyll, somewhat similar to YuniaGumuiaG. zyzzataZosterophyllalesOne of the most well-known Posongchong plantsHalleophytonH. zhichangenseDrepanophycalesAnother possible species also known from the formationHedeiaH. sinicaProgymnospermopsida?Resembles both seed plants and trimerophytesHicklingiacf. Hicklingia sp.ZosterophyllalesResembles the type species of the genus, but bears a few differences from itHueberiaH. zhichangensisDrepanophycales?Also resembles Leclercqia, however lack of anatomy means its position is unclear.HuiaH. recurvataRhyniopsida?Likely related to RenaliaOrnicephalumO. sichuanenseZosterophyllopsidaFormerly classed within ZosterophyllumPauthecophytonP. gracileTrimerophytaRelated to PsilophytonPolythecophytonP. demissumProgymnospermopsida?Likely related to Hedeia and AneurophytalesPsilophytonP. primitivumTrimerophytaOne of the most widespread basal vascular plantsRamoferisR. amaliaZosterophyllalesClosely resembles ZosterophyllumRiccardiothallusR. devonicusAneuraceaeEarliest simple thalloid liverwort knownStachyophytonS. yunnanenseTracheophyta incertae sedisDivergent from other plants due to its leaf-like branches and other featuresWenshaniaW. zhichangensisZosterophyllalesClosely resembles ZosterophyllumYuniaY. dichotoma, Y. guangnaniaZosterophyllopsida?Possibly closer to euphyllophytes than zosterophylls?ZhengliaZ. radiataProtolepidodendrales?May preserve the earliest lycophyte ligulae ZosterophyllumZ. australianum, Z. ramosum, Z. minifertillum, Z. tenerumZosterophyllalesKnown from numerous other localities
Animals
AnimalsGenusSpeciesHigher taxonMaterialNotesImagesArquatichthysA. porosusDipnomorphaOnly known from scales and skull materialBrevipetalichthysB. gracilisPetalichthyidaEuporosteusE. yunnanensisActinistiaEarliest known anatomically modern coelacanthGantarostrataspisG. gengiGantarostrataspidae (Galeaspida)Bears an unusual sensory systemG. sp. indet.A partial rostral process.GumuaspisG. rostrataHuananaspidaeResembles LaxaspisHuananaspisH. wudinensisHuananaspidaeAlso known from the Nagaoling FormationLungmenshanaspisL. yunnanensisHuananaspidae (Galeaspida)From a different locality to the "main" Posongchong Formation, yet correlates with it in ageMacrothyraspisM. longicornis Macrothyraspidae (Galeaspida)Bears unusually long cornual and rostral processesM. longilanceusComplete rim of the ventral headshield.Osteolepiformes indet.UnapplicableOsteolepiformesCannot be placed within a genusPaleolophusP. yunnanensisDipnoiOne of the earliest lungfish, shows rapid evolution of various skull characteristicsPanjiangosteusP. eurycephalaAntarctaspidaePetalichthyidaIndeterminatePetalichthyidaAn incomplete vental head shield wall.QingmenaspisQ. microculusGaleaspida incertae sedisBears similar unornamented regions to osteostracan "lateral fields"QingmenodusQ. yuiOnychodontidaeThe first onychodont to preserve the otoccipital region of the skullRhegmaspisR. xiphoideaGantarostrataspidae (Galeaspida)Likely quite active as shown by its streamlined head shieldSanqiaspisS. rostrataSanqiaspididae (Galeaspida)Species also known from VietnamS. zhaotongensisPartial headshield.SarcopterygiiIndeterminateSarcopterygiiTwo scales.TungseniaT. paradoxaTetrapodomorphaMost basal and earliest known tetrapodomorphWenshanaspisW. zhichangensisZhaotongaspididae (Galeaspida)Differentiated by its cornual processesW. sp.An incomplete headshieldYiminaspisY. shenmeWuttagoonaspidaeSuggests a Chinese origin of the familyYunnanolepidoideiIndeterminateYunnanolepidoideiAn incomplete dorsal trunk shield wall.ZhaotongaspisZ. janvieriZhaotongaspididae (Galeaspida)Bears the highest quantity of branchial fossae known in agnathans
References