Lineage of Arxina schwageri (Silvestri, 1928) new genus (Nummulitacea) from Middle Eocene of Egypt and Sultanate of Oman

Four species, Arxina parva (Douville, 1930), Arxina cf. schwageri (Silvestri, 1928) A. schwageri (Silvestri, 1928) and Arxina sp. cf. alpina (Douville, 1916) assigned to the newly erected genus Arxina, are recorded from the Middle Eocene of Egypt and Sultanate of Oman. The phylogenetic trend of these species exhibits a progressive increase in the size, a flattening of the test and a general trend of the coalescence of granules which become smaller in size.     

New latest Permian foraminifers from Laren (Guangxi Province, South China): Palaeobiogeographic implications

Microfacies analyses performed on the latest Permian Wujiaping Formation at Laren (Guangxi Province, South China) show that the bioclastic-rich limestones of Late Permian age contain a rich and well-diversified foraminiferal fauna. This fauna is here revised in order to be compared with time-equivalent levels of southern Iran and southern Turkey. Some new and unexpected phylogenetic trends are highlighted among the biseriamminoids. The new or poorly known genera Retroseptellina, Septoglobivalvulina, Paraglobivalvulinoides, Dagmarita?, Bidagmarita nov. gen., Louisettita, Paradagmaritopsis nov. gen. and Paradagmarita? are concerned. Nevertheless, these newly appeared biseriamminoids are subordinate to abundant Tetrataxis and Climacammina, ultimate survivors of the families Palaeotextulariidae and Tetrataxidae, appeared as old as the Early Carboniferous (“Mississippian”). Algae, miliolids, and nodosarioids are poorly represented. Two genera and four species are here newly described: Globivalvulina curiosa nov. sp., Louisettita ultima nov. sp., Bidagmarita nov. gen., Bidagmarita sinica nov. gen. nov. sp., Paradagmaritopsis nov. gen., Paradagmaritopsis kobayashii nov. gen. nov. sp. The palaeogeographic distribution of these foraminifers is interpreted to be typically of Neo-Tethyan regions, ranging from southern Turkey (Hazro) to South China (Laren) and up to Japan for some species (i.e., Paradagmaritopsis). At Laren, Late Permian strata are generally characterized by Reichelina ex gr. simplex Sheng. Isolated samples of packstones, collected in Tsoteng region (Guangxi Province, South China), contain Sphaerulina sp. together with various smaller foraminifers and numerous representatives of the new species G. curiosa nov. sp. In this study we demonstrate that the regions of Zagros (Iran), Taurus (Turkey), South China and even Japan shared similar foraminiferal assemblages and represented intermittently connected palaeobiogeographic provinces during Late Permian times.     

Late paleozoic and Late Triassic limestones from north Palawan Block (Philippines): Microfacies and paleogeographical implications

Summary Selected Late Paleozoic and Triassic limestone exposures were studied on northern Palawan Island, Philippines, with regard to microfacies, stratigraphy and facies interpretation. Although some of the outcrops were already reported in literature, we present the first detailed microfacies study. Late Paleozoic carbonates in the El Nido area are represented by widley distributed Permian and locally very restricted Carbonifenous limestones. Of particular interest is the first report of Carboniferous limestones in the Philippines dated by fossils. Fusulinids indicate a ‘Middle’ Carboniferous (Moscovian-Kasimovian) age of the Paglugaban Formation only known from Paglugaban Island. The Permian Minilog Formation consists mostly of fusulinid wackestones and dasycladacean wacke-/packstones. Fusulinid datings (neoschwagerinids and verbeekinids) provide a Guadalupian (Wordian-Capitanian) age. The depositional setting of the Middle Permian carbonates corresponds to a distally steepened ramp with biostromes built by alatoconchid bivalves locally associated with richthofeniid brachiopods. Late Triassic limestones occur in isolated exposures on and around Busuanga Island (Calamian Islands). The age of the investigated carbonates is Rhaetian based on the occurrence ofTriasina hantkent Maizon. Microfacies data indicate the existence of reefs (Malajon Island) and carbonate platforms (Kalampisanan Islands, Busuanga Island, Coron Island). Reef boundstones are characterized by abundant solenoporacean red algae, coralline sponges and corals. Platform carbonates yield a broad spectrum of microfacies types, predominantly wacke- and packstones with abundant involutinid foraminifera and some calcareous algae. These facies types correspond to platform carbonates known from other parts of Southeast Asia (Eastern Sulawesi and Banda Basin; Malay Peninsula and Malay Basin). The Philippine platform carbonates were deposited on and around seamounts surrounded by deeper water radiolarian cherts. The new data on facies and age of the Philippine Permian and Triassic carbonates contradict a close paleogeographical connection between the North Palawan Block and South China and arise problems for the currently proposed origin of the North Palawan Block at the paleomargin of South China. We hypothesize that North Palawan was part of the Indochina Block during the Carboniferous and Permian, separated from the Indochina Block during the Middle Permian and collided with the South China Block in the Late Cretaceous.     

Strengths abd weaknesses of the reef guild concepts and quantitative data: Application to the upper Capitan-massive community (Permian), Guadalupe Mountains, New Mexico-Texas

Summary Analyses of large acatate sheet tracings, close-up photos and 105 sub-horizontal quadrat surfaces at four localities near the base of the Guadalupe Mountains Escarpment indicate that the biotic framework of the upper Capitan reef was built by about 35 species: one codiacean (Eugonophyllum sp.), 17 calcisponges, 9 bryozoans, one richthofenid brachipod, some crinoid (known only from columns), 4 Problematica and microbes. This widespread fossil community included members of the Constructor, Baffler and Binder Guilds. A re-evaluation of the Guild Concept (Fagerstrom, 1987, 1991) highlights the validity of the functional roles of the Constructor and Binder Guilds for reef construction. Members of the Baffler Guild, however, need to be revised and an interpretation of microbial micrite and cryptic biota remains controversial. Open surface phylloid algal and cryptic sponge-bryozoan dominated sub-communities were of only local importance. The upper Capitanmassive differs from its Permian conterparts in the low diversity and areal cover of the frame-building biota, low micrite content and abundant micro-frameworks, i.e, intergrown small sponges, Problematica and syndepositional cements (botryoidal and isopachous, fibrous calcite). Quantitative areal cover data were assessed at various scales. Large acetate sheets generally have low coverage of macro-biota (5.4%). By contrast, analysis of small areas of local high areal cover (selected acetate sheet quadrats, subvertical photographs, and quadrat samples: 15–21%) provide detailed insights into clustered patches forming the inital reef framework. Both data sets provide useful clues for an integrated approach to framework assessment. Mean acetate sheet data are limited by their somewhat generalized pattern, while small investigation areas may overemphasize local variation. Erect and pendant sponges with solitary, sub-cylindrical and multi-branche/clonal forms, were the predominant initial frame-builders in both open surface and cryptic habitats. Selective larval recruitment of erects sponges to firm substrates produced continous upward accretion of the initial framework. On open surfaces and in pores formed by tabular sponges and fenestrate bryozoans, erect and pendant sponges were supported in their hydrodynamically unstable growth position by encrusters, chieflyArchaeolithoporelle hidensis, Shamovella obscura, an unnamed tubular organism, and microbes. Subsequent growth ofArchaeolithoporella hidensis, microbial crusts and syndepositional cements on the outer walls of live sponges would have impeded ambient water circulation and may have led to ‘creeping sponge death by suffocation’ or complete encrustation after death. Filling of pores in the initial and encrusted reef framework by internal sediment (packstone-grainstone; derived from the framework and the back-reef shelf/platform) and voluminous syndepositional marine-phreatic cements completed the framebuilding process.     

Changhsingian (Late Permian) foraminifers from the topmost part of the Xiala Formation in the Tsochen area,central Lhasa Block,Tibet and their geological implications

A foraminiferal fauna consisting of 15 genera and 19 species is documented for the first time from the topmost part of the Xiala Formation in the Aduogabu area in Tsochen County, central Lhasa Block. This foraminiferal fauna is dominated by Colaniella, indicating a broadly Changhsingian age. The presence of Colaniella, Reichelina and absence of the typical tropical fusuline genus Palaeofusulina in the fauna indicate that the Lhasa Block has not merged into equatorial regions during the Changhsingian. More importantly, the widespread Lopingian (Late Permian) marine carbonates with warm-water faunas and the stable platform carbonate sequence through the Guadalupian and Lopingian in the Lhasa Block present an obvious contrast against the contemporaneous sequences in the South Qiangtang Block and Gondwana margin. It suggests that both the Bangong-Nujiang Ocean and the Neotethys Ocean would have opened by the Guadalupian and Lopingian.     

A Wuchiapingian (Late Permian) brachiopod fauna from an exotic block in the Indus–Tsangpo suture zone, southern Tibet, and its palaeobiogeographical and tectonic implications

A brachiopod fauna including 19 species of 17 genera from an exotic block in the Indus–Tsangpo suture zone in southern Tibet is described and illustrated. The brachiopod fauna is dominated by Martinia elegans and two new taxa: Jinomarginifera lhazeensis gen. et sp. nov. and Zhejiangospirifer giganteus sp. nov. The fauna is closely comparable with those from the middle and upper parts of the Wargal Formation and the Chhidru Formation in the Salt Range of Pakistan, the Chitichun Limestone in southern Tibet, and the Basleo area of West Timor, and these correlations suggest a Wuchiapingian age. The fauna exhibits substantial links with both peri–Gondwanan and Cathaysian faunas, which may imply that it is a seamount biota originally located in the southern margin of the Neotethys during the Late Permian, and was later (in the early Cenozoic) displaced and became sandwiched into younger marine deposits in the collision process between India and Eurasia.     

Middle-late Asselian (Early Permian) fusulinid fauna from the post-Variscan cover in NW Anatolia (Turkey): Biostratigraphy and geological implications

The earliest autochthonous cover of the Variscan basement of the Sakarya Composite Terrane (SCT) in NW Anatolia is represented by basal conglomerates and limestones. The microfacies types of the limestones in ascending order are: (1) bioclastic grainstone/packstone, (2) fusulinid grainstone/packstone, (3) smaller foraminiferal grainstone/packstone, (4) Anthracoporella (dasycladale) grainstone/packstone, and (5) wackestones. Twenty-three species assignable to 15 genera of fusulinids were recovered from the studied materials of the Kadirler section; Quasifusulinaguvenci nov. sp. and Pseudoschwagerinabeedeimagna nov. subsp. are created. Rugosofusulinids, sphaeroschwagerinids, pseudoschwagerinids, occidentoschwagerinids, pseudochusenellids, quasifusulinids, rugosochusenellids and paraschwagerinids are the main faunal elements of the succession, which shows two distinct faunal intervals. Eoschubertella, Schubertella, Biwaella?, Rugosofusulinastabilis group, and Pseudochusenella correspond to the first interval at the base; the second interval is characterized by the species of Sphaeroschwagerina, Pseudoschwagerina,Occidentoschwagerina, the Rugosofusulinalatispiralis group, and diverse quasifusulinids. A biostratigraphic correlation shows that the Kadirler section in the SCT in NW Anatolia shares many common species with Central Asia in the East but especially with the Carnic Alps and Karavanke Mountains in the West. The new data suggest that the close faunal relationship in the Late Carboniferous between eastern Alps, Ural Mountains, NW Turkey and Central Asia also continued during the Asselian.     

Biologic response to environmental stress in tropical reefs: Lessons from modern Polynesian coralgal atolls and Middle Permian sponge and Shamovella-microbe reefs (Capitan Limestone USA)

Despite prejudices that comparisons of paleoecological patterns in modern and fossil reef communities are of doubtful validity, we compare the biologic response of living coralgal reefs in French Polynesia to environmental stress with an exceptionally well exposed Middle Permian sponge reef and Shamovella-microbial reef of the Capitan Limestone in New Mexico. In the western Tuamotu Archipelago, reef margins are characterized by depth-related changes of biodiversity. The subtidal basic reefbuilding community contains the highest diversity (23 coral and 6 calcareous algal species). With decreasing water depth and increasing environmental stress, diversity reaches a minimum of five taxa on the reef flat. The Capitan consists of two reef stages. Reefbuilders of the lowermost exposed part of Stage 1 formed a cement-rich sponge reef with 42 taxa (28 sponge species). Decreasing water depth along the reef face is accompanied by loss of five taxa, variations in the gross morphology of sponges and changes in framework architecture. Stage 2, dominated by Shamovella obscura, one bryozoan species and microbes, is sandwiched between two unconformities suggesting much shallower water and higher environmental stress. Despite differences in shelf profile and taxonomy, both the modern and Permian reefbuilders respond to increasing environmental stress with diversity impoverishment and dominance of binders.     

Cranial anatomy and phylogenetic position of Suminia getmanovi, a basal anomodont (Amniota: Therapsida) from the Late Permian of Eastern Europe

Suminia getmanovi , a recently discovered basal anomodont from the Late Permian of Russia, is characterized by robust, 'leaf-shaped' teeth, and a masticatory architecture that is similar to that of the highly diverse and cosmopolitan group of Permo-Triassic herbivores, Dicynodontia (Anomodontia). Based on new material, the skull is reconstructed in three dimensions and described in detail. A cladistic analysis of the basal anomodonts, Patranomodon, Galeops, Otsheria, Ulemica , and Suminia , using 37 cranial characters, resulted in a single most parsimonious tree, in which Suminia is united with the Russian taxa, Ulemica and Otsheria. This clade, diagnosed by four unambiguous characters, is designated as Venyukovioidea. The South African anomodont, Galeops , appears as the sister taxon to Dicynodontia. Patranomodon is the most basal anomodont. The cladistic analysis suggests that a 'dicynodont-type' masticatory architecture, with an expanded adductor musculature and sliding jaw articulation, may have originated prior to the advent of the (Venyukovioidea + ( Galeops + Dicynodontia)) clade.     

A new diverse shark fauna from the Wordian (Middle Permian) Khuff Formation in the interior Haushi‐Huqf area,Sultanate of Oman

Abstract: Chondrichthyans are newly reported from the autochthonous Wordian Khuff Formation (middle Permian), cropping out in well‐exposed, low‐palaeolatitude sections in the interior Haushi‐Huqf area of Oman. The shark remains comprise isolated teeth, dermal denticles and fin spines and have been recovered by processing limestone in buffered acetic acid from bulk rock samples. The fauna consists of mainly ctenacanthiform and hybodontiform taxa, identified as Glikmanius cf. myachkovensis, Glikmanius culmenis sp. nov., Omanoselache hendersoni gen. et sp. nov., Omanoselache angiolinii gen. et sp. nov., cf. Omanoselache sp., Reesodus underwoodi gen et sp. nov., Teresodus amplexus gen. et sp. nov., Gunnellodus bellistriatus, Khuffia lenis gen. et sp. nov., Khuffia prolixa gen. et sp. nov. and Euselachii sp. indet. Additional specimens include rare teeth of the lonchidiid cf. ‘Palaeozoic Genus 1’ sp., of the neoselachian Cooleyella cf. fordi and a further indeterminate neoselachian, of an indeterminate petalodont and of the holocephalan Deltodus aff. mercurei and Solenodus cf. crenulatus. Fin spines add a further two taxa, Nemacanthus sp. and Amelacanthus cf. sulcatus, which have neoselachian affinities and therefore an unclear relationship to the recovered teeth. The occurrence of Nemacanthus within this Wordian fauna represents the oldest record of this taxon and its only known occurrence in the Palaeozoic. Of the remaining genera, Glikmanius has previously been recorded from the Wordian, whereas for all the others, this study represents their youngest known stratigraphic occurrence and first occurrence in Guadalupian (middle Permian) strata. This adds significantly to our knowledge of the global diversity of chondrichthyans preceding the end‐Guadalupian biotic crisis. Palaeogeographically, for all taxa, this study represents the first record from the western fringe of the marine Neotethyan basin, and only Cooleyella was previously known from the southern (Gondwanan) part of the Pangaean continental margin.     

Hyloidichnus bifurcatus Gilmore, 1927 and Limnopus heterodactylus (King, 1845) from the Early Permian of Southern Alps (N Italy): A New Equilibrium in the Ichnofauna

Studies on Early Permian tetrapod ichnofauna emphasized the scarcity of forms from Italian sites. A revision work on the entire collections revealed the presence of Hyloidichnus bifurcatus Gilmore, 1927 and Limnopus heterodactylus (King, 1845). The ichnoassociation now lists seven ichnogenera: Amphisauropus, Batrachichnus, Dromopus, Erpetopus, Hyloidichnus, Limnopus, Varanopus. These new data enlarge the ichnoceonosis, adding tracks of medium-size captorhinomorphs (Hyloidichnus) and temnospondyls (Limnopus) to the Italian ichnofauna, previously characterized by scarcity of predators and amphibians. Radiometric ages give a strong age constraint to the ichnoassociation (Early Kungurian), allowing useful correlations to contemporary successions all over the world. The main difference is the absence of Ichniotherium and Dimetropus, and this could have a stratigraphic or paleoenvironmental significance. The fauna is similar in two main basins, Collio and Orobic. It differs solely in the proportions between ichnotaxa, with a predominance of areoscelid traces (Dromopus) in the Collio Basin and of captorhinomorph traces (Erpetopus, Varanopus, Hyloidichnus) in the Orobic Basin. This datum could reflect slightly different environments, seasonal in the Collio Basin (alluvial plain) and more arid in the Orobic Basin (playa-like). The lack of some forms in smaller basins of the Athesian Volcanic Complex is probably due to a bias.     

河南许昌灵井遗址的晚更新世鹿科化石新种类

记述了在近几年从河南省许昌市灵井旧石器遗址出土的1个鹿科化石新亚种: 灵井山西轴鹿新亚种(Axis shansius lingjingensis sub sp.nov.)和1个属、种未定的潜在新种。前者角冠的主枝呈琴弓状, 并有一定程度的螺旋状, 目前是轴鹿属在晚更新世的唯一代表;后者的角冠在角环上方同一位置向不同的方向伸出3个分枝, 与鹿亚科其他成员的角冠在角环上方只有主枝和眉枝(或第一枝)的情况完全不同,而介于晚中新世的皇冠鹿(Stephanocemas)和中、晚更新世的大角鹿(Megaloceros)之间。     

Linguaserra spandeli sp. nov. (Echinodermata: Ophiocistioidea) from the Late Permian (Zechstein) of Thuringia, Germany

From the Late Permian Zechstein reefs (Lopingian: Wuchiapingian) of eastern Thuringia, Germany, the new ophiocistioid goniodont Linguaserra spandeli sp. nov., is described, figured, and discussed, within the Linguaserridae Reich and Haude, 2004. The (para)genus Linguaserra is redefined; the stratigraphical and regional distribution as well as the phylogenetic position are briefly discussed. Linguaserra spandeli sp. nov. is the stratigraphically youngest record of this echinoderm group (Echinozoa: Ophiocistioidea) worldwide.     

Osteology of Rauisuchus tiradentes from the Late Triassic (Carnian) Santa Maria Formation of Brazil,and its implications for rauisuchid anatomy and phylogeny

As the eponymous type species for rauisuchians, Rauisuchus tiradentes von Huene, 1938 represents an important but inadequately known specimen. The revision of the type material from the Upper Triassic (Carnian) Santa Maria Formation of Brazil reveals new anatomical data and previously unrecognised characters, including three new possible autapomorphies: a knob‐like thickening on the base of the posterior process of the premaxilla; short and ventrally keeled cervicals lacking postzygodiapophyseal laminae; and mid‐caudal vertebrae with an accessory neural spine and a postspinal lamina. Several elements are re‐identified, including a postorbital (originally identified as postfrontal) and a pterygoid (originally identified as a prefrontal), and additional material from a secondary fossil site, originally assigned to R. tiradentes, including a left ilium, is excluded. Based on the recovered information and new morphological data, the systematic position of R. tiradentes is tested in a comparison of two phylogenetic reanalyses. Both analyses differ in respect to the phylogenetic position of R. tiradentes, and recover ‘rauisuchians’ as a paraphyletic assemblage of non‐crocodylomoprh archosaurs. © 2014 The Linnean Society of London     

A nearly complete skeleton of an early juvenile diplodocid (Dinosauria: Sauropoda) from the Lower Morrison Formation (Late Jurassic) of north central Wyoming and its implications for early ontogeny and pneumaticity in sauropods

A nearly complete skeleton of a juvenile sauropod from the Lower Morrison Formation (Late Jurassic, Kimmeridgian) of the Howe Ranch in Bighorn County, Wyoming is described. The specimen consists of articulated mid-cervical to mid-caudal vertebrae and most appendicular bones, but cranial and mandibular elements are missing. The shoulder height is approximately 67 cm, and the total body length is estimated to be less than 200 cm. Besides the body size, the following morphological features indicate that this specimen is an early juvenile; (1) unfused centra and neural arches in presacral, sacral and first to ninth caudal vertebrae, (2) unfused coracoid and scapula, (3) open coracoid foramen, and (4) relatively smooth articular surfaces on the limb, wrist, and ankle bones. A large scapula, short neck and tail and elongate forelimb bones relative to overall body size demonstrate relative growth. A thin-section of the mid-shaft of a femur shows a lack of annual growth lines, indicating an early juvenile individual possibly younger than a few years old. Pneumatic structures in the vertebral column of the specimen SMA 0009 show that pneumatisation of the postcranial skeleton had already started in this individual, giving new insights in the early ontogenetic development of vertebral pneumaticity in sauropods.

The specimen exhibits a number of diplodocid features (e.g., very elongate slender scapular blade with a gradually dorsoventrally expanded distal end, a total of nine dorsal vertebrae, presence of the posterior centroparapophyseal lamina in the posterior dorsal vertebrae). Although a few diplodocid taxa, Diplodocus, cf. Apatosaurus, and cf. Barosaurus, are known from several fossil sites near the Howe Ranch, identification of this specimen, even at a generic level, is difficult due to a large degree of ontogenetic variation.     

A palaeolithic map from 13,660 calBP: engraved stone blocks from the Late Magdalenian in Abauntz Cave (Navarra, Spain)

An engraved block from the cave of Abauntz is interpreted as a Magdalenian map in which the actual surrounding landscape, including mountains, rivers, and ponds, is represented. Some possible routes or avenues of access to different parts of the geography are also engraved on the landscape. The engraving seems to reproduce the meandering course of a river crossing the upper part of side A of the block, joined by two tributaries near two mountains. One of these is identical to the mountain that can be seen from the cave, with herds of ibex depicted on its hillsides, on both sides of the gorge in front of which the cave of Abauntz is strategically located. In the southern part of the gorge, there is a completely flat area where the watercourses slow down, forming meanders and flooding in springtime. The following elements are also represented on the block: tangles of concentric strokes and bundles of lines forming very marked meanders. In short, all of these engravings could be a sketch or a simple map of the area around the cave. It could represent the plan for a coming hunt or perhaps a narrative story of one that had already happened. This paper is provided in the context of recent discussions on early modern human capacities of spatial awareness, planning, and organized hunting.     

Late Oligocene mesotheriids (Mammalia, Notoungulata) from Salla and Lacayani (Bolivia): implications for basal mesotheriid phylogeny and distribution

The oldest known mesotheriids are referred to the genus Trachytherus , a taxon traditionally included in its own subfamily 'Trachytheriinae'. The ontogeny, morphological variation and systematics of the genus Trachytherus are still poorly understood and the monophyly of this taxon is questionable. For the first time, a large collection of basal mesotheriids (belonging to the genus Trachytherus ) yielded by the Bolivian Salla beds (Deseadan, late Oligocene) and previously referred to T. spegazzinianus was included in a large-scale analysis. This has led to the recognition of a unique new species in the locality of Salla-Luribay, distinct from T. spegazzinianus : Trachytherus alloxus sp. nov . Skulls of this species are described and cheekteeth variation range throughout ontogeny is discussed. These new data are incorporated in a parsimony analysis of basal mesotheriids. The most probable hypothesis of a clade T. spegazzinianus -mesotheriines is discussed. The distinction of the new Salla species from the Patagonian species T. spegazzinianus confirms the faunal differences observed between these Bolivian and Patagonian Deseadan localities. Moreover, the assignment to Trachytherus spegazzinianus of mesotheriid remains from the Bolivian Lacayani deposits complicates the problem of these faunal differences. Further systematic investigations on the Lacayani fauna and on the age of the Patagonian localities are needed.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 153–200.     

New insights from bone microanatomy of the Late Triassic Hyperodapedon (Archosauromorpha,Rhynchosauria): implications for archosauromorph growth strategy

Bone microanatomy of multiple postcranial skeletal elements of several individuals of Hyperodapedon collected from India is reported. This reveals that fibrolamellar bone tissue is predominant in the mid‐ and inner cortices, whereas the peripheral region of the cortex is composed of either parallel‐fibred and/or lamellar bone. The pattern of primary osteons mostly ranges between laminar and subplexiform. Such predominance of fibrolamellar bone tissue in the cortex suggests an overall fast growth, which slowed down considerably later in ontogeny. Four distinct ontogenetic stages are identified based on the bone microstructure. During the juvenile stage, growth was fast and continuous, but it became punctuated during the early and late sub‐adult stages. In adult individuals, growth was slow and showed periodic interruption but did not stop completely, suggesting that Hyperodapedon had an indeterminate growth strategy. Interelemental histovariations affecting cortical thickness, organization of the vascular network, incidence of growth rings and extent of secondary reconstruction are noted. Throughout ontogeny, the femora show higher cortical thickness than humeri and tibiae, suggesting differential appositional growth rate between the skeletal elements. Differences in cortical thickness are noted in the ribs, which suggest differential functional constraints based on anatomical site‐specific occurrences. Although fibrolamellar bone tissue became progressively more dominant towards the archosaurs, there are considerable variations in the growth patterns of the archosauromorphs. This is exemplified by the bone microstructure of Hyperodapedon, which deviates from the generalized slow‐growth pattern proposed for all basal archosauromorphs, suggesting that rapid growth was already present in the archosauromorphs. The cortical thickness of various long bones of Hyperodapedon bears similarity with that of several extant terrestrial quadrupeds, suggesting that Hyperodapedon was essentially a terrestrial quadruped.