The morphology and histology of a juvenile Sinokannemeyeria from the Middle Triassic Ermaying Formation of Shanxi, North China

Kannemeyeriiformes were dominated tetrapods in the Middle Triassic terrestrial faunae of China.Although abundant materials of Sinokannemeyeria have been collected, their postcranial morphology information is not well studied, especially the juveniles. This paper presents a description of an articulated Sinokannemeyeria skeleton from the Middle Triassic Ermaying Formation and reports the histological microstructure of its femur. This specimen represents a late-stage juvenile based on the histological information. For the first time, this specimen offers insights into the postcrania information of juvenile Sinokannemeyeria.

Biodiversity and Sequence of the Middle Triassic Panxian Marine Reptile Fauna,Guizhou Province,China

The Middle Triassic Panxian fauna is a physical marker and representative record of the rapid recovery of the Triassic marine ecosystem following the Early Triassic stagnant stage after the end-Permian mass extinction. Ten marine reptile taxa have been found from the 1.82-2.10 m-thick fossiliferous level in the Upper Member of the Guanling Formation, which can be subdivided into three marine reptile beds through the analysis on the stratigraphic distributions of fossil reptiles. The Lower Reptile Bed yields the sauropterygians Placodus inexpectatus Jiang et al., 2008 and Lariosaurus hongguoensis Jiang et al., 2006, the ichthyopterygians Xinminosaurus catactes Jiang et al., 2008 and Phalarodon cf. Phalarodon fraasi Merriam, 1910, associated with Mixosaurus panxianensis Jiang et al., 2006, representing a stage of predominance of durophagous taxa. In this bed, the large complete skeletons may reach up to 2.3 m in length, and lithofacies and chemostratigraphic analyses indicate a relatively deep carbonate platform with an oxic water environment near the bottom, as well as a rising sea level The Middle Reptile Bed yields the sauropterygian Nothosaurus yangjuanensis Jiang et al., 2006 and the archosaur Qianosuchus mixtus Li et al., 2006, associated with Mixosaurus panxianensis Jiang et al., 2006. The fossils in this bed are characterized by its pincering dentition and large overall body size, with the largest possibly exceeding 3 m in length. This bed might represent a time of deepest basin with relatively anoxic condition near the bottom. The Upper Reptile Bed yields the sauropterygians Wumengosaurus delicatomandibularis Jiang et al., 2008, Keichousaurus sp., the protorosaur Dinocephalosaurus orientalis Li, 2003, and the ichthyopterygian Mixosaurus panxianensis Jiang et al., 2006. In this bed, reptilian taxa characterized by suction feeding appeared, and most are less than 1 m long. This bed corresponds to a period of decreasing water depth.

First Record of Protorosaurid Reptile (Order Protorosauria) from the Middle Triassic of China

A new genus and species of the family Tanystropheidae, Dinocephalosaurus orientalis gen. et sp. nov., is described based on a nearly complete skull. This is the first record of the order Protorosauria from China. It also represents the only known occurrence of Tanystropheidae outside Europe, the Middle East and North America. Dinocephalosaurus is quite similar to Tanystropheus from Monte San Giorgio, Switzerland. Primarily it is distinguished from Tanystropheus in the shape of the premaxilla, maxilla, jugal and parietal. Although the family Tanystropheidae is now referred to the order Protorosauria, the new material from China indicates that the archosauromorph affinities of tanystropheids need further investigation. The discovery of Dinocephalosaurus provides new clues for the study of the evolution and radiation of Protorosauria and Tanystropheidae. It is also important for the study of the eastern Tethyan Fauna and the paleobiogeographical relationship between Europe and southern China in the Triassic.

A New Perleidiform(Actinopterygii,Osteichthyes)from the Middle Anisian(Middle Triassic)of Yunnan,South China

Two complete specimens from the Pelsonian （Middle Anisian, Middle Triassic） of Luoping, Yunnan Province, South China are referred to a new actinopterygian genus, Luopingichthys gen. nov., and ascribed to the perleidiform family Polzbergidae based especially on a typical synapomorphy of a peculiar premaxillary-maxillary complex, i.e., the fusion between premaxillary and maxillary along the antero-dorsal margin of the maxillary. The new taxon differs from other deep-bodied representatives of the family, Felberia and Stoppania, in its fusiform or deep fusiform body shape; sickle-shaped preopercular with short infraorbital process; lack of modified scales at the base of the anal fin; the short-based dorsal fin; scarcely ornamented scales; and thin anterior teeth. Based on a redescription of the holotype of the taxon Ctenognathichthys hattichi from the Middle Triassic （Ladinian） Prosanto Formation, Canton Graubiinden, eastern Switzerland, the only known specimen, which shows the same fusion between premaxillary and maxillary, the systematic position of the species is clarified and the taxon is proposed to be a further representative of the family Polzbergidae, and is transferred to the new genus.

Intracontinental Collisional Orogeny During Late Permian-Middle Triassic in South China: Sedimentary Records of the Shiwandashan Basin

Sedimentary response to an orogenic process is important for determining whether South China had compressional or extensional orogeny during the period from the Late Permian to the Middle Triassic besides the tectonic and magmatologic evidence. An intracontinental collision event took place between the Yangtze and Cathaysia blocks in the Late Permian. Beginning at the Late Triassic, the tectonic movement was completely changed in nature and entered a post-collisional extensional orogenic and basin-making process. This paper presents sedimentological evidence from the Late Permian to the Middle Triassic in the Shiwandashan basin at the southwestern end of the junction zone between the Yangtze and Cathaysia blocks.

New species of Saurichthys(Actinopterygii:Saurichthyidae)from Middle Triassic(Anisian)of Yunnan Province,China

Saurichthys dawaziensis sp. nov., from the third member of the Gejiu Formation （Anisian of Middle Triassic） in the vicinity of Luoping, Yunnan Province, is a small to mediumsized saurichthyid fish. It is characterized by the efferent pseudobranchial arteries penetrating on the parasphenoid and the mandible sensory canal with a branch in the angular. The new species is more derived than the Lower Triassic species in having a relatively narrow postorbital region, short preopercular, single ossification of the sclerotic ring, small haemal arches between the pelvic fins and the anal fin without ossified spines, and in the absence of quadratojugal. It is more primitive than the Middle and Upper Triassic Saurichthys in having fringing fulcra and numerous segments in the unpaired fins, and the presence of both prae- and post-zygapophyses in the neural arches. Some anatomic changes related to the vertebral column and unpaired fins of the genus are also discussed.

Sedimentary Facies Architectures of Third-Order Sequences from Early to Middle Triassic in Nanpanjiang Basin

There are complex and regular changes on sedimentary facies from the Early to the Middle Triassic in the Nanpanjiang basin. After the obvious drowned event of carbonate platforms in the transitional period between Permian and Triassic, carbonate platforms have evolved into the ramp type from the rimmed shelf type. The differentiation of sedimentary facies becomes clearer in space, which are marked by the changes from an attached platform to a turbidity basin and several isolated platforms in the basin. The striking characteristics are the development of oolitic banks on isolated platforms in Nanning and Jingxi and the reef and bank limestones in the margin of the attached platform in the Early Triassic. Despite the difference of the time span and the architecture of facies succession of third order sedimentary sequences, the process of the third order relative sea level changes reflected by the sedimentary facies succession of the third order sequences is generally synchronous. Therefore, six third order sequences could be discerned in the strata from the Early to the Middle Triassic in the Nanpanjiang basin. Using two types of facies changing surfaces and two types of diachronisms in stratigraphic records as the key elements, the sedimentary facies architectures of the third order sequences that represent sequence stratigraphic frameworks from the Early to the Middle Triassic in the Nanpanjiang basin could be constructed.

Study of the Early and Middle Triassic Lower Yangtze Sea Basin

The Early and Middle Triassic primary lower Yangtze sea basin was formed before the Yangtze and Sino. Korean blocks collided and were assembled. showing the characteristics of an open continental shelf.continental margin sea. In order to provide evidence useful for oil and gas exploration in the studied region, this paper centres on the features of the sediments and their facies framework in the basin and the sedimentation parameters such as the deposition rate, palaeotemperature, palaeosatinity, palaeodepth of water and palaeocurrents of the basin.

Stratigraphic Correlation of Middle TriassicSequences among Different Paleogeographic Sedimentary Facies in South China

Affected by the Indosinian movement, the sediments in the main part of South China, Yangtze platform, started to transform from marine to continental during the Middle Triassic. In the meantime, a noticeable paleogeographic and sedimentary facies differentiation occurred in the marginal regions of the platforms and produced completely different lithologic and paleontologic sequences in various paleogeographic gradients and sedimentary facies areas, which brought about the difficulties for the stratigraphic correlation based on the traditional stratigraphies. This paper proposes to use some characteristic environmental events as the markers of the stratigraphic correlation across various paleogeographic sedimentary facies, considering that some distinctive regional environmental events should have affected at the same time on the entire basin or the connected sedimentary regions and produced some closely related sedimentary records in the stratigraphic sequences though the affected intensity and recorded pattern might be different among the regions. The change of violent relative sea level (generally water depth) and the alteration of tectonic activity summarized from the dynamic mechanism of sedimentation are the best markers of environmental events for stratigraphic correlation. Based on the analysis and recognition of some significant environmental events at the typical stratigraphic sequences from various paleogeographic sedimentary facies and combined with the consideration of the variations in expressed form and strength of the events among different paleogeographic gradients and sedimentary facies, the stratigraphic sequences from different sedimentary facies can be easily correlated directly. Furthermore, the evolutionary history of the whole sedimentary basin can be clearly established.

Middle Triassic Stratigraphy and Sedimentary Paleogeography of South China

The Middle Triassic was the great turning period of South China from marine sedimentary basins to continental deposits or erosion. This paper summarizes the distribution and variation of the stratigraphic sequences, lithofacies and biotas in various Middle Triassic depositional basins of South China. The close relationship between the biotic paleoecology and the lithofacies as well as the sedimentary facies, thus the paleogeography, is demonstrated. The process of the transition from the depositional paleogeography and its relation to the tectonic settings is concluded.

Ichnofabrics and Their Environmental Interpretation from the Fluvial Deposits of the Middle Triassic Youfangzhuang Formation in Western Henan, Central China

Fluvial deposits from the Middle Triassic Youfangzhuang Formation in Henan Province, China contain a low-diversity trace fossils. Vertical dwelling burrows of opportunists dominate in active channel, whereas horizontal deposit-feeding, grazing, and vertical dwelling burrows occur in overbank deposits. Seven recurrent ichnofabrics were distingushed. The Palaeophycus tubularis ichnofabric pre- serves below scour interface between two fluvial cycles. The Skolithos linearis ichnofabric forms in middle to high-energy, soft substrates in the middle and upper parts of active channel deposits under semi-arid climate. The Skolithos linearis-Planolites montanus ichnofabric occurs in the sediments just a little above the Skolithos linearis ichnofabric and is formed in middle-energy, soft substrates in the up- per part of active channel deposits. The Planolites montanus ichnofabric is mostly preserved in associa- tion with medium- to thick-bedded brown-red silty mudstones or siltstones in low-energy, perennial muddy bottom ponds in overbank settings. The Taenidium barretti ichnofabric is interpreted as peri- odically exposed ephemeral ponds or low-energy distal floodplain. The Skolithos isp. ichnofabric com- monly occurs in middle to high-energy firm ground of proximal foodplain or crevasse-splay deposits. The root trace iehnofabric occurs in the crevasse splay deposits. The presence of thin palaeosols and the abundance of calcretization in mudstones indicate a seasonal climate ranging from humid to semi-arid, with high temperature, rainfall, and well-defined dry and wet seasons.

Petrochemistry and Tectonic Setting of the Middle Triassic Arc-Like Volcanic Rocks in the Sayabouli Area,NW Laos

The volcanic rocks from the Sayabouli area in northwestern Laos have been poorly studied. These volcanic rocks are traditionally mapped as the Permian–Early Triassic sequences on the geological map. One basaltic-andesite from the Sayabouli area yields a zircon U-Pb age of 237.7±1.7 Ma, suggesting a Middle Triassic origin. All basalt and basaltic-andesite samples from the Sayabouli area show depletions in HFSEs（e.g., Nb, Ta, Ti） and have high LILE/HFSE ratios, and exhibit the geochemical affinity to the continental arc volcanic rocks and are geochemically similar to the continental arc volcanic rocks from the Phetchabun belt in northeastern Thailand, suggesting a Late Permian–Middle Triassic continental margin in the Sayabouli area of northwestern Laos and Phetchabun area of northeastern Thailand. Our data indicate that the Phetchabun arc volcanic belt through the western Loei sub-belt can be linked to the Sayabouli area in northwestern Laos.

Palaeoecological Analysis of Trace Fossil Sinusichnus sinuosus from the Middle Triassic Guanling Formationin Southwestern China

The Luoping Biota discovered from the early Middle Triassic （Anisian） Guanling Formation of southwestern China represents a fully recovered shallow marine ecosystem, marking the end point of Early Triassic biotic recovery following the end-Permian mass extinction. Contemporaneously preserved are prolific trace fossils, which offer good opportunities to understand the palaeoecology of marine invertebrates from a fully recovered shallow marine ecosystem. Here we present a newly discovered sinuous branching burrow from the fossil-bearing unit in Member II of the Guanling Formation. Several features, including the horizontal regular sinuous nature, the branching pattern, typical H-junction, and the small wavelength/amplitude ratio of these sinuous structures within the burrow systems justify assignment of these traces as Sinusichnus sinuosus, a trace possibly produced by decapod crustaceans. Close association ofS. sinuosus with Rhizocorallium commune suggests a deposit-feeding strategy of these trace makers. The newly reported Anisian material from the Guanling Formation in Luoping represents first report of Sinusichnus from South China. The global record of Sinusichnus occurrence suggests that these burrows might have an older history than Early Middle Triassic.

Microbially Induced Carbonate Precipitation in a Middle Triassic Microbial Mat Deposit from Southwestern China:New Implications for the Formational Process of Micrite

Lime mud(i.e.,micrite)is a major component of carbonate deposits.Various mechanisms(biotic versus abiotic)have been proposed for the formation of lime mud in Earth’s history.However,the detailed role that microbes play in the nucleation and subsequent precipitation of micrites remains to be resolved.Herein we undertook a detailed geobiological characterization of laminated lime mudstone from the Middle Triassic Guanling Formation in Yunnan Province,southwestern China.Morphological features,together with previous geobiological investigations,suggest that the laminated lime mudstones represent the former presence of microbial mats.These lime mudstones consist mainly of calcite,dolomite and quartz,with clay minerals and pyrites as subordinate components.In particular,micro-analysis shows copious nano-globules(65–878 nm)and capsule-shaped nano-rods in laminations.These low-Mg calcite nano-globule aggregates are closely associated with mucilaginous biofilms resembling extracellular polymeric substances(EPS).Nano-sized globules coalesce to form semi-euhedral micrite crystals.We suggest that a decaying hydrolytic destruction of the EPS by microbial communities within microbial mat leads to the precipitation of the nano-globules by enhancing alkalinity in local micro-environment.As an intermediate,these nano-globules further aggregate to form micrite crystals possibly through a dissolution-reprecipitation process.

Stratigraphic Definition and Correlation of Middle Triassic Volcaniclastic Facies in the External Dinarides： Croatia and Bosnia and Herzegovina

Middle Triassic volcaniclastic depositsin the External Dinarides of Croatia and Bosnia and Herzegovina are related to the rifting of the Tethyan Ocean. Three localities in the External Dinarides： Donje Pazariste, Bosansko Grahovo and Zelovo were biostratigraphically analysed in this study. The Middle Triassic carbonate deposits with volcaniclastic interlayers in Donje Pazariste were defined by means of conodonts. Rare ammonoid specimens were collected.Recovered conodont and ammonoid taxa suggest these sections are of Early Illyrian to Early Fassanian Age. The section studied in Bosansko Grahovo is dominantly composed of volcanic and volcaniclastic rocks. Limestone peperites were collected for conodont analysis. Two conodont zones were defined, suggesting volcanic activity in the same, from Lower Illyrian to Fassanian, time interval. The Zelovo Section was biostratigraphically investigated by several authors. The pietra verde deposits from Zelovo are referred as late Fassanian to Early Longobardian Age. Biostratigraphic correlation from mentioned three localities imply that the magmatic activity in the External Dinarides, and formation of different volcaniclastic facies lasted from Illyrian to Longobardian, similar as in the surrounding western Tethyan territories.

Petrogenesis of Middle Triassic Volcaniclastic Rocks from Balochistan,Pakistan:Implications for the Break-Up of Gondwanaland

Basaltic volcanic conglomerates near the Wulgai village in Balochistan occur in the undivided sedimentary rock unit of the Bagh complex which is the mélange zone beneath the Muslim Bagh ophiolite. The presence of Middle Triassic grey radiolarian chert within the upper and lower horizon of the conglomerates suggests that the lavas, from which these conglomerates were principally derived, were eroded and re-deposited in the Middle Triassic. The Wulgai conglomerate contains several textural and mineralogical varieties of volcanic rocks, such as porphyritic, glomerophyric, intersertal and vitrophyric basalts. The main minerals identified in these samples are augite, olivine, plagioclase（An35–78） leucite and nosean, with apatite ilmenite, magnetite and hematite occurring as accessory minerals. These rocks are mildly to strongly-alkaline with low Mg~# and low Cr, Ni and Co contents suggesting that their parent magma had undergone considerable fractionation prior to eruption. Trace element-enriched mantle-normalized patterns with marked positive Nb anomalies are consistent with 10%–15% melting of an enriched mantle source in a within-plate tectonic setting. It is proposed that this Middle Triassic intra-plate volcanism may represent mantle plume-derived melts related to the Late Triassic rifting of micro-continental blocks（including Afghan, Iran, Karakorum and Lhasa） from the northern margin of Gondwana.

Middle Triassic(Anisian)Conodont Biostratigraphy at the Shaiwa Section,Guizhou,South China

The Nanpanjiang Basin is a key area for paleontological and biostratigraphical study of the Middle Triassic.Herein we studied Middle Triassic conodonts from a well-exposed section,the Shaiwa Section,which is located at the northwest end of the Nanpanjiang Basin.A total of six Anisian conodont zones are recognized;in ascending order,they are:the Nicoraella germanica Zone,the Nicoraella kockeli Zone,the Paragondolella bulgarica Zone,the Neogondolella constricta Zone,the Neogondolella cornuta Zone,and the Paragondolella excelsa Zone,respectively.The first occurrence of Nicoraella kockeli defines the Bithynian-Pelsonian boundary.The Pelsonian-Illyrian boundary is defined by the first occurrence of Neogondolella constricta.The Anisian-Ladinian boundary cannot be recognized at the Shaiwa Section due to the absence of conodont indicative of the Ladinian.However,the new conodont data indicate that the uppermost strata could be very close to the boundary.The abrasion of conodont surfaces provides evidence for demonstrating reworking at the Shaiwa Section,which makes some conodonts possess a longer stratigraphic range than previously recorded.The variation in relative abundance between blade-shaped conodonts and platform conodonts indicates that segminiplanate elements probably preferred deeper and oxygenated environments whereas a restricted marine environment is more suitable for segminate elements.

Patterns of fossil distributions within their environmental context from the Middle Triassic in South Canyon,Central Nevada,USA

The Middle Triassic records the return of diverse marine communities after the severe effects of the end-Permian mass extinction.This diversification leads to the Mesozoic/modern adaptive radiation resulting in substantial changes in marine communities in comparison to their Paleozoic predecessors.This analysis focuses on the faunal abundance,ecological patterns,and environmental interpretation of a Middle Triassic section in Central Nevada.Twelve bulk samples were collected.Visible fossils were identified and tallied from hand samples and thin-sections were used to aid in environmental interpretation.Beginning in the Late Anisian,we observed an ammonoid dominated to flat-clam,epifaunal dominated benthic community within a muddy,quiet,inner shelf depositional environment.Through time,epifaunal bivalves dominate within a middle shelf environment followed by an increase in infaunalization and shell-thickness.During this time the presence of oncoids and the reported finding of corals suggest the middle shelf environment gave way to a higher energy patch reef shelf edge environment.Finally,we observe epifaunal brachiopods communities at the top of our section deposited in a middle shelf environment.In sum,we observe the dominance of modern taxa(i.e.,bivalves)with Paleozoic ecologies(i.e.,epifaunal),followed by the dominance of modern taxa with Modern ecologies(i.e.,infaunal,thick shells)and then a return to Paleozoic taxa(i.e.,brachiopods)and Paleozoic ecologies within an overall transgressive environment.

Lithofacies palaeogeography and biostratigraphy of the lowermost horizons of the Middle Triassic Hallstatt Limestones (Argolis Peninsula,Greece)

Condensed ammonoid beds of the Hallstatt facies (Anisian-Ladinian) are widespread around the Ancient Theatre of Epidaurus,in the locality Theokafta of the Argolis Peninsula (eastern Peloponnesus).The Hallstatt Formation in Argolis appears,generally,in the form of lensoid bodies of variable sizes,inclination and direction and is always found overlying a formation consisting of keratophyric tuffs.In fact,the contact of the keratophyric tuffs with the overlying limestones,specifically evidenced by an in situ brecciated zone,is stratigraphic and constitutes the base of the Hallstatt Limestones.The contact of the Hallstatt Limestones with the overlying radiolarites is stratigraphic as well.Lithofacies and biostratigraphic research has focused on the lowermost horizons of the Hallstatt Limestones of Anisian age (average thickness about 1.30 m),where a dense sampling has been performed,followed by detailed facies analysis.The lowermost horizons of the Hallstatt Limestones of Theokafta represent typical hiatus beds/concretions sensu Wetzel and Allia (2000),characterized by discontinuous sedimentation and erosion.They consist of red ammonoid-bearing hemipelagic limestones with calcium carbonate nodules floating in an enriched Fe-oxides matrix with dispersed lensoid/prismatic calcium carbonate crystals.This part of the section is characterized by condensed sedimentation,due to significant lowering of the rate of sedimentation and includes omission surfaces,firmgrounds and hardgrounds along certain horizons.Nine lithostratigraphic units have been distinguished in the lowermost horizons of the Hallstatt Limestones,including radiolarian packstones,volcaniclastic facies,packstones/floatstones with ammonoids and lag deposits.Tselepidis (2007) defined nine distinct ammonoid biozones from the Anisian to Ladinian,documenting deposition of the Hallstatt facies during a low depositional rate over nearly 5 million years (using the timescale of Gradstein et al.,2004).The biozones:Japonites/Paracrochordiceras,Hollandites,Procladiscites/Leiophyllites,zoldianus,trinidosus,Reitziites/Parakellnerites and the Nevadites (Anisian) and the biozone curionii (Lower Ladinian).Although sedimentation was very condensed,it didn’t reach the level of mixing fauna.Synsedimentary and early burrowing processes differentiated the primary texture characteristics of the deposited sediments.Multiphase diagenesis occurred not very deep below the sediment surface and includes boring and/or encrustation,burial and cementation.The deposition of the studied Hallstatt Limestones is considered to be due to anaerobic oxidation of organic matter,which provided excess alkalinity,inducing carbonate precipitation.Sedi-mentation took place on differentially-subsided deep swells.After drowning,the swells were covered by pelagic carbonate deposits.Further slight rotation of blocks,along listric faults,may have led to additional differential subsidence of the blocks.Shelf bathymetry and thirdorder sea-level changes played a significant role in the formation of the Hallstatt beds.In terms of sequence stratigraphy,the studied hiatus concretions and beds are considered genetically linked to rising or high sea-level,formed at the initiation of transgressions,as well as during the time of maximum rate of transgression,in areas where the sediment input was strongly reduced (’’condensed section’’) .Taking into consideration the present location of the Hallstatt Formation,in the context of the Hellenides,an area suitable for the deposition of the Hallstatt Limestones,should be located between the sub-Pelagonian (western part of the Pelagonian zone) and Pindos geotectonic zones,which during the Triassic corresponded to a platform slope and a deep ocean,respectively.The widespread Middle Triassic Han Bulog Limestones (ammonoid-bearing pelagic limestones) from Triassic successions of the Eastern Alps (Dinarides,Hellenides) may have formed partly in similar slope environments.

The Most Complete Pistosauroid Skeleton from the Triassic of Yunnan,China

A new specimen discovered from the Falang Formation in northeastern Yunnan represents the most complete skeleton of Triassic pistosauroids. The new specimen is referred to Yunguisaurus Cheng et al., 2006 on the basis of the skull features, such as the presence of a separated nasal entering the external naris, a large pineal foramen located at the frontal/parietal suture and an interpterygoid vacuity with a narrow anterior extension. The new specimen differs from the type species of Yunguisaurus liae Cheng et al., 2006 in some aspects. Most of these differences can be attributed to ontogenetic variations. The new specimen is provisionally considered as Yunguisaurus cf. liae although its relatively short snout of the skull and slenderer hyoid may not be explained ontogenetically. Whether or not the new specimen represents a different taxon has to wait for a detailed study of the whole skeleton.