Fact-checked by Grok 2 weeks ago

Nothosaur

Nothosaurs (superfamily Nothosauroidea) were Triassic marine sauropterygian reptiles belonging to the clade Nothosauria within Sauropterygia, which thrived in shallow epicontinental seas during the Middle to Late Triassic period, approximately 247 to 210 million years ago.^[1]^[2] These lizard-like animals typically measured 2.5 to 4 meters in length, though some species like Nothosaurus zhangi reached up to 7 meters, featuring a streamlined body, elongated neck and tail, short limbs modified into paddles for swimming, and conical or fang-like teeth suited for grasping prey such as fish and cephalopods.^[1]^[3] Fossils of nothosaurs are primarily known from Tethyan marine deposits in Europe, North Africa, and Asia, including notable sites in the Germanic Basin and Luoping biota of China, with recent discoveries extending to the Southern Hemisphere, such as a 246-million-year-old vertebra from New Zealand representing the oldest known Southern Hemisphere sauropterygian.^[1]^[4]^[5] They formed part of diverse coastal ecosystems recovering from the Permian-Triassic extinction. As early members of Eosauropterygia, nothosaurs exhibited key adaptations for aquatic life, including pachyostotic ribs for buoyancy, an elongate trunk with approximately 19-24 cervical vertebrae, and elongated neural spines that supported axial undulation for propulsion in near-shore habitats.^[3]^[4]^[6] Their dentition and robust jaws indicate an ambush predatory lifestyle targeting soft- and hard-shelled invertebrates as well as smaller vertebrates, contributing to the rapid diversification of Mesozoic marine reptiles.^[1]^[4] Paleohistological studies of humeri reveal lamellar-zonal bone growth patterns, suggesting moderate growth rates and potential longevity exceeding 20 years in some individuals, with evidence from multiple specimens pointing toward viviparous reproduction in at least certain populations to adapt to unstable marine conditions.^[2] The group includes several genera, such as Nothosaurus from European localities and the gigantic N. zhangi from southwestern China, highlighting regional variations in size and possibly ecology across the Pangaean shelves.^[1] Trackways attributed to nothosaurs further demonstrate their ability to haul out onto land, underscoring a semiaquatic lifestyle akin to modern marine iguana.^[7] Overall, nothosaurs represent a pivotal stage in sauropterygian evolution, bridging basal forms like Hanosaurus and later plesiosaurs, and underscoring the Triassic's role as a cradle for marine reptile radiations.^[3]

Description

Body plan

Nothosaurs possessed an elongated, semi-aquatic body plan characterized by a streamlined form adapted for life in shallow marine environments. Their bodies typically measured 2–4 meters in length, with some species reaching up to 5–7 meters, as seen in the gigantic Nothosaurus zhangi from the Middle Triassic of China.^[1] This structure featured a long neck, comprising 17 to 24 cervical vertebrae across species (up to 19 in Nothosaurus mirabilis), which could account for approximately 20% of the total body length in larger individuals, facilitating maneuverability in water.^[6] The axial skeleton included an elongated trunk with around 20–26 dorsal vertebrae, supporting a robust ribcage that enhanced buoyancy through pachyostosis, a condition of bone thickening common in semi-aquatic reptiles.^[6] The tail was powerful and elongated, with at least 22 caudal vertebrae in N. mirabilis, providing propulsion via lateral undulation during swimming.^[6] Overall, the dorsoventrally flattened body, including a relatively small and flattened skull, contributed to hydrodynamic efficiency.^[8] Variations existed among genera; for instance, Nothosaurus exhibited a stockier build suited for ambush predation, while Lariosaurus xingyiensis displayed a more serpentine form with 20 cervical and 24 dorsal vertebrae in a smaller body (around 1 meter), emphasizing agility in coastal habitats. These proportions underscore the group's adaptations for both aquatic foraging and occasional terrestrial movement.^[9]

Skull and dentition

The skull of nothosaurs is characteristically elongated and dorsoventrally flattened, facilitating streamlined movement through aquatic environments.^[10] This morphology includes large temporal fenestrae that accommodate hypertrophied jaw adductor musculature, enabling powerful bites essential for capturing elusive prey.^[11] The orbits are positioned dorsally and anterolaterally, with proportionally large openings that suggest enhanced visual acuity for detecting prey underwater, potentially supporting binocular vision through neck mobility.^[11] Dentition in nothosaurs features sharp, conical teeth with fine vertical ridges and a circular cross-section, arranged in a single row forming a dense palisade along the jaws.^[12] These teeth point slightly outward and are recurved, adaptations ideal for grasping and securing slippery prey such as fish and cephalopods without crushing them.^[12] Some species exhibit heterodonty, with enlarged anterior canines for initial piercing and smaller posterior teeth for maintaining grip during feeding.^[10] In the genus Nothosaurus, evidence from well-preserved specimens reveals needle-like teeth reaching up to approximately 2 cm in length, particularly in larger individuals, further indicating a primarily piscivorous lifestyle.^[12] For instance, N. rostellatus displays maxillary canines around 14-15 mm, with replacement teeth mirroring functional ones in shape and size to ensure continuous predatory efficiency.^[12]

Limbs and appendages

The limbs of nothosaurs underwent significant modifications toward aquatic adaptation, transforming the forelimbs and hindlimbs into paddle-like structures that facilitated efficient swimming while retaining limited terrestrial functionality. These appendages featured elongated phalanges and instances of hyperphalangy—an increase in the number of phalangeal elements per digit beyond the ancestral condition—along with webbed digits that enhanced propulsive surface area.^[13] In the manus of species like Nothosaurus luopingensis, the phalangeal formula is typically 2-3-4-5-3, with expanded ungual phalanges on the first two digits contributing to a broadened paddle shape, though hyperphalangy is absent in some taxa.^[14] The proximal limb elements, including the humerus and femur, were robust and adapted for load-bearing in an aquatic environment. Nothosaur humeri exhibit a curved shaft with a triangular mid-shaft cross-section, a straight preaxial margin, and a distinct deltopectoral crest, forming a dorsoventrally flattened, hydrofoil-like profile that supported lift-based propulsion.^[13]^[15] Femora are generally slender and biconcave, with a reduced internal trochanter and slightly expanded proximal head, indicating less specialization compared to the humerus.^[14] These features allowed for some grasping capability on land, consistent with the semi-aquatic lifestyle inferred from bone histology showing lamellar zonal tissue indicative of intermittent terrestrial exposure.^[16] Variations exist among nothosaur genera, reflecting a gradient from primitive to more derived forms. In advanced nothosaurs like Nothosaurus, the paddles are more flattened and rounded, with hyperphalangy enhancing digit elongation for streamlined swimming.^[13] Primitive pachypleurosaurs, such as Lariosaurus, display hyperphalangy in both manus and pes but retain more claw-like terminal phalanges and less modified humeri, suggesting greater terrestrial proficiency.^[17]^[14] Fossil evidence reveals asymmetric limb pairs, with forelimbs often larger and more derived for primary propulsion and steering, while hindlimbs are plesiomorphic and suited for maneuvering.^[13]^[15] In Nothosaurus luopingensis, for instance, the forelimb is shorter and stouter than the hindlimb, highlighting functional differentiation preserved in articulated specimens from the Middle Triassic.^[14]

Classification

Etymology and definition

The genus name Nothosaurus, the type genus of Nothosauria, derives from the Ancient Greek words nothos (illegitimate or spurious) and sauros (lizard), coined by Christian von Münster in 1834 to reflect the animal's ambiguous, transitional morphology between terrestrial reptiles and fully aquatic forms.^[18] This etymology highlights early perceptions of nothosaurs as "spurious lizards" due to their semi-aquatic adaptations, such as elongated bodies and partially webbed limbs, which defied strict categorization at the time of discovery.^[6] Nothosauria represents a stem-group clade within the broader subgroup Eosauropterygia of secondarily aquatic sauropterygian reptiles, encompassing marine forms from the Middle to Late Triassic that bridge basal lizard-like ancestors and more derived plesiosauromorphs.^[19] The clade is diagnosed by key synapomorphies including an elongate neck with an increased number of cervical vertebrae (typically 17–24 in most genera), limbs modified into paddle-like structures with hyperphalangy (increased phalangeal count) for enhanced propulsion in water, and dentition adapted for aquatic predation, ranging from conical teeth for grasping fish in Nothosauridae to crushing dentition in Simosauridae.^[1]^[20] It traditionally includes the families Nothosauridae (encompassing genera such as Nothosaurus, Lariosaurus, Germanosaurus, and Ceresiosaurus) and Simosauridae (primarily Simosaurus and Paludidraco), totaling approximately 6 valid genera across its diversity. The scope of Nothosauria excludes more basal pachypleurosaurs (e.g., Pachypleurosaurus and Keichousaurus), which lack the advanced aquatic specializations of nothosaurs and form a sister group, though broader classifications sometimes unite them under the superfamily Nothosauroidea.^[19] The monophyly and validity of Nothosauria as a distinct clade have been robustly supported by recent phylogenetic analyses, particularly those integrating new fossil discoveries from Asian Lagerstätten such as the Luoping and Yunnan biotas, which reveal diverse morphologies reinforcing shared diagnostic traits and evolutionary coherence within Eosauropterygia.^[21]^[19]

Taxonomic history

The first fossils attributable to the genus Nothosaurus, the type genus of Nothosauria, were discovered in March 1834 at the Oschenberg quarry near Laineck, Bayreuth, in southern Germany, within the Upper Muschelkalk Formation of the Middle Triassic (Anisian stage).^[22] These remains, consisting of an incomplete skeleton (holotype UMO 1000), were excavated by Count Georg Graf zu Münster, a prominent early 19th-century paleontologist known for his contributions to Bavarian fossil collections.^[22] Münster formally named the specimen Nothosaurus mirabilis later that year, noting its blend of plesiosaur-like and crocodilian features alongside distinctive limb structures that set it apart from known reptiles.^[22] Subsequent detailed examinations by Hermann von Meyer in 1847–1855 corrected Münster's initial misinterpretations of certain elements, such as vertebrae and limb bones, establishing a more accurate reconstruction of the skeleton.^[22] Nothosaurus became the foundational genus of the group, with over ten valid species currently recognized, including N. edingerae, N. giganteus, N. haasi, N. jagisteus, N. marchicus, N. mirabilis, N. tchernovi, N. winterswijkensis, N. youngi, and N. zhangi; earlier proposals included many synonymous or invalid names, such as Conchiosaurus clavatus absorbed into N. mirabilis and Paranothosaurus into N. edingerae.^[23] Other key genera within Nothosauria include Lariosaurus, a smaller form (typically under 1 meter long) known primarily from Italian fossils discovered starting in 1830 at Perledo near Lake Como, where an almost complete holotype was unearthed from Middle Triassic deposits; it was named Lariosaurus balsami in 1847 by Giulio Curioni, honoring the ancient name "Larius" for the lake. Simosaurus, another significant genus, is distinguished by its crocodile-like skull featuring a blunt, flattened profile, large upper temporal fossae exceeding the eye sockets in size, and robust, blunt teeth adapted for crushing shelled prey, with remains first described from French and German Triassic sites in the mid-19th century. Twentieth-century taxonomic revisions significantly streamlined Nothosauria by merging redundant species and resolving synonymies, with later discoveries, particularly from Asia, expanding the recognized diversity within Nothosaurus based on cladistic analyses that aligned morphological traits with stratigraphic occurrences across the Germanic Muschelkalk and Keuper formations.^[23] This work, exemplified by Rieppel and Wild's 1996 monograph, emphasized faunal exchanges between Germanic and Alpine regions during the Anisian-Ladinian boundary, while declaring junior synonyms like Conchiosaurus and Paranothosaurus obsolete to stabilize nomenclature.^[23] Such mergers highlighted the challenges of early descriptions reliant on fragmentary material, leading to ongoing refinements in estimates of nothosaur diversity. A notable recent addition is Dianmeisaurus mutaensis, described in 2024 from an immature skeleton (holotype HFUT MT-21-08-001, approximately 99 mm long) recovered from the Upper Member of the Anisian Guanling Formation in Yunnan Province, southwestern China; this basal pachypleurosaur exhibits autapomorphies such as a postfrontal extending beyond the parietal midpoint and a stout final dorsal rib shorter than the first sacral rib.^[24] Phylogenetic analyses position D. mutaensis as sister to D. gracilis, forming the basal-most clade within a monophyletic Pachypleurosauria alongside Panzhousaurus, thereby expanding the known range of early nothosauroids into eastern Tethyan margins.^[24] Ongoing controversies have centered on the inclusion of pachypleurosaurs within Nothosauria, with traditional views treating Pachypleurosauria as a monophyletic sister group to Eusauropterygia (encompassing Nothosauroidea and Pistosauroidea), though some analyses questioned this monophyly and suggested paraphyly or closer ties to pistosaurs.^[24] Recent studies from 2023–2024, incorporating expanded datasets with 52 Triassic sauropterygian taxa, have largely resolved this by recovering Pachypleurosauria as monophyletic and positioned as the sister taxon to Nothosauroidea, collapsing broader Eusauropterygia monophyly while affirming the distinction between these groups.^[24] This framework, supported by D. mutaensis's basal placement, underscores an eastern Tethys origin for pachypleurosaurs and reinforces Nothosauria's core composition around genera like Nothosaurus, Lariosaurus, and Simosaurus.^[24]

Phylogenetic relationships

Nothosauria is positioned within the clade Eosauropterygia, a major subgroup of Sauropterygia that encompasses the early-diverging marine reptiles of the Triassic period, with Nothosauria serving as a basal group relative to the more derived Plesiosauria.^[3] Within Eosauropterygia, Nothosauria is typically recovered as part of Nothosauroidea, where it forms a monophyletic group comprising Nothosauridae and Simosauridae, positioned as the sister taxon to Pachypleurosauria in broader analyses of sauropterygian relationships.^[25] This placement is supported by cladistic analyses incorporating morphological data from cranial, vertebral, and appendicular characters, highlighting Nothosauria's role as a transitional lineage bridging early, more terrestrial-adapted sauropterygians to the fully pelagic plesiosaurs of the Jurassic and Cretaceous.^[3] Key synapomorphies defining Nothosauria include an elongate neck with increased cervical vertebrae (typically 17–24, though up to 42 in some like Lijiangosaurus jiaoi as of 2025), which facilitated greater maneuverability in aquatic environments compared to basal relatives; reduced or absent dermal armor, contrasting with the osteoderm-covered placodonts and some pachypleurosaurs; and specialized limb paddles characterized by hyperphalangy and broadened phalanges, precursors to the hydrofoil-like flippers of plesiosaurs.^[20]^[26] These features underscore the group's evolutionary adaptations for semi-aquatic to fully marine lifestyles, with the elongate neck and paddle-like limbs providing evidence of gradual specialization toward the body plans seen in later Sauropterygia.^[3] Recent phylogenetic updates from 2024 have refined our understanding of nothosaurian divergence. Fossils from New Zealand, including a nothosaur vertebra dated to the Anisian stage of the Middle Triassic (~246 Ma), represent the oldest sauropterygian record in the Southern Hemisphere and support an early Gondwanan dispersal of Nothosauria from a Tethyan origin, indicating rapid global radiation shortly after the end-Permian extinction.^[27] Concurrently, the description of Dianmeisaurus mutaensis, a basal pachypleurosaur from southwestern China, clarifies branching patterns at the base of Pachypleurosauria—sister to Nothosauroidea—by demonstrating monophyly within the clade and an eastern Tethys cradle for early eosauropterygian diversification.^[25] In summary cladograms from tip-dated Bayesian analyses, Nothosauria (encompassing Nothosauridae and Simosauridae) branches during the Middle Triassic, forming a successive outgroup to Pistosauroidea and ultimately ancestral to the long-necked plesiosaurs, with divergence estimates placing the Nothosauria-Pachypleurosauria split in the Early Triassic.^[3] This positioning emphasizes Nothosauria's pivotal role in the adaptive radiation of Sauropterygia, linking short-necked basal forms to the iconic long-necked giants of later Mesozoic seas.^[25]

Fossil record

Temporal range

Nothosaurs, members of the superfamily Nothosauroidea, first appeared in the Early Triassic during the Olenekian stage, approximately 251 million years ago, shortly after the end-Permian mass extinction.^[28] Basal forms are recorded from Early Triassic sediments in Asia, including specimens of Lariosaurus from South China, marking the initial radiation of this marine reptile group into shallow marine environments.^[29] Their temporal range extended through the Middle Triassic, with the group achieving peak diversity in the Anisian and Ladinian stages (approximately 247–237 million years ago), as evidenced by abundant and varied fossils from lagerstätten such as the Luoping biota in China and the Muschelkalk in Europe.^[1] Nothosaurs persisted into the Late Triassic, with records extending to approximately 210 million years ago. This decline coincides with the Carnian Pluvial Episode, a period of profound global environmental perturbation characterized by increased humidity, temperature shifts, and volcanism-linked changes that triggered extinctions in various marine taxa, potentially contributing to the nothosaurs' disappearance.^[30] Recent discoveries, including a 2024 report of a nothosaur vertebra from the Middle Triassic (Anisian, ~246 million years ago) of New Zealand's Balmacaan Formation, confirm the group's presence in southern high latitudes during its early diversification phase but do not alter the established temporal bounds of ~251–210 million years ago.^[27] This specimen underscores the rapid post-extinction dispersal of nothosaurs while aligning with their known stratigraphic distribution primarily in the Tethyan realm.00375-0)

Geographic distribution

Nothosaurs, a group of Triassic marine reptiles, are primarily known from fossil sites along the margins of the Northern Tethys Ocean, where the majority of discoveries have been made in coastal and shallow marine deposits of the Middle Triassic. In Europe, significant localities include the Muschelkalk Formation in southwestern Germany, such as the Oschenberg site near Bayreuth, which has yielded well-preserved specimens of Nothosaurus mirabilis and other species, representing key type localities for the genus.^[31] Additional European sites encompass the Lower Muschelkalk of the Germanic Basin, including areas in the Netherlands near Winterswijk and eastern Germany, where Nothosaurus marchicus fossils indicate a broad distribution across the basin.^[32] In northern Italy and adjacent Switzerland, nothosaurids like Lariosaurus have been recovered from the Besano Formation at Monte San Giorgio, a UNESCO site preserving articulated skeletons that highlight the group's presence in lagoonal environments.^[33] France's Alsace region, particularly Lothringen, also contributes to this record through fossils associated with the Bayreuth fauna, extending the known range westward.^[6] Further east, in Asia, the Luoping Biota of Yunnan Province, China, represents a major hotspot, with the Guanling Formation yielding diverse nothosaurs including the gigantic Nothosaurus zhangi and the pachypleurosaur Dianmeisaurus mutaensis, indicating a rich eastern Tethyan assemblage.^[34]^[35] Other Asian localities include Middle Triassic deposits in the Middle East, such as sites in the Negev (Israel) preserving nothosaur species, underscoring the group's prevalence along the Tethyan seaway from Europe to East Asia.^[36] The Southern Hemisphere record, long sparse, was dramatically expanded by the 2024 discovery of a nothosaur vertebra (GNS CD 540) in the Balmacaan Formation of New Zealand's [South Island](/page/South Island), dating to the early Middle Triassic (~246 Ma) and marking the oldest known occurrence in the region.^[5] This find, from Balmacaan Stream near Mt. Harper, suggests early high-latitude dispersal into the Panthalassic Ocean.^[37] Additional sites include Poland's Silesian region with isolated nothosaur remains and trackways from Middle Triassic seabeds in Spain's Valdelcubo locality, contributing to a total of approximately 20 major fossil-bearing areas worldwide.^[7] Possible traces in North America, such as early eosauropterygian fossils with nothosauroid affinities from British Columbia, Canada (~247 Ma), hint at trans-Arctic connections.^[5] Biogeographically, nothosaurs originated in the northeastern Tethys and rapidly expanded westward along northern margins and southward to Gondwanan shelves, with the New Zealand specimen evidencing circum-Gondwanan dispersal to polar latitudes (>60° S) by the early Middle Triassic, challenging earlier Eurocentric models of a more restricted, northern distribution and supporting a pattern of vicariance driven by post-extinction recovery and oceanic connectivity.^[5]^[38]

Paleoecology

Habitat and lifestyle

Nothosaurs primarily inhabited shallow epicontinental seas and restricted lagoons within the Tethys Ocean and its connected basins during the Middle Triassic.^[10] Fossils from the Muschelkalk Formation in the Germanic Basin, which includes lagoonal deposits with evaporites, indicate a preference for nearshore environments characterized by fluctuating salinity and periodic storm events. These settings featured unstable marine conditions with alternating regressions and transgressions, supporting a diverse array of coastal marine life. Their lifestyle was semi-aquatic, with adaptations enabling both aquatic propulsion and terrestrial movement, akin to modern pinnipeds such as seals. Limb structures, including robust humeri and webbed digits, suggest capability for hauling out onto land, possibly for thermoregulation or resting, though some evidence points to viviparity that may have reduced reliance on terrestrial egg-laying. Smaller-bodied species, like Nothosaurus marchicus, were likely surface swimmers in shallow waters, maintaining positive buoyancy through osteosclerotic bones, while larger forms evolved reduced skeletal density for more efficient open-water cruising.^[10] In contemporaneous ecosystems, nothosaurs coexisted with other marine reptiles such as pachypleurosaurs, placodonts, and early pistosaurs in biodiverse Tethyan reefs and coastal zones teeming with fish and invertebrates.^[10] A notable Early Triassic nothosaur vertebra from New Zealand's southern polar region, dated to approximately 246 million years ago, indicates tolerance for cooler, high-latitude shallow coastal environments beyond the typical tropical Tethys, hinting at broader ecological versatility. Nothosaurs demonstrated adaptations to warm, tropical waters with tolerance for salinity variations, as evidenced by their abundance in evaporite-influenced strata of the Muschelkalk, where restricted circulation led to hypersaline episodes. This resilience likely facilitated their radiation across fluctuating epicontinental seas, from nearshore lagoons to marginally deeper habitats.

Diet and feeding

Nothosaurs were primarily piscivorous predators, specializing in fish and soft-bodied cephalopods as evidenced by rare preserved gastric contents in articulated fossils, which include fish remains and cephalopod fragments.^[1] Coprolites attributed to nothosauroid marine reptiles from the Luoping Biota contain abundant fish scales and bone fragments, further supporting a diet dominated by schooling fish and other small aquatic vertebrates at higher trophic levels.^[39] This predatory niche is consistent across nothosaur genera, with adaptations for capturing elusive prey in shallow marine environments. The feeding apparatus of nothosaurs featured a lateral jaw gape enabled by a kinetic quadrate, allowing rapid closure to seize prey, complemented by conical, recurved teeth that formed a grasping palisade for impaling slippery targets like fish.^[40] Needle-like maxillary canines, up to 14 mm long with fine vertical ridges, facilitated piercing and retention of soft-bodied cephalopods, while asynchronous tooth replacement ensured continuous functionality during strikes.^[40] Enhanced neck mobility, inferred from elongated cervical vertebrae and flexible articulations in genera like Nothosaurus, likely aided precise head extension for ambush predation in coastal waters.^[1] Direct evidence from fossilized stomach contents and coprolites highlights a focus on abrasive, scaled prey.^[39] Tooth morphology, including slender precanine and postcanine denticles, points to a carnivorous lifestyle targeting mobile, soft prey rather than hard-shelled organisms.^[40]

Locomotion and behavior

Nothosaurs employed paraxial locomotion in aquatic environments, primarily propelled by lateral undulation of their long, laterally compressed tail, which generated thrust through undulatory waves along the body axis.^[41] Forelimb paddles, adapted with rounded, webbed structures and histological features indicating resistance to torsional forces, augmented propulsion and facilitated maneuvering, potentially employing an underwater flight-like motion.^[41] Hindlimbs, smaller and more flexible, likely served for steering and stability during swimming.^[41] On land, nothosaurs could perform short-distance crawls using a sprawling gait with their clawed, webbed limbs, enabling them to haul out onto beaches or shallows for resting or breeding, consistent with their semi-aquatic lifestyle.^[42] Fossil trackways from Middle Triassic coastal sediments, including paddle impressions, support this amphibious capability, showing alternations between underwater paddling and surface propulsion.^[43] Behaviorally, nothosaurs are inferred to have been solitary or small-group ambush predators in shallow marine settings, targeting fish and cephalopods with rapid lunges, though direct evidence of sociality remains absent from fossil assemblages lacking mass bone beds.^[41] Reproductive strategies likely included viviparity, as indicated by humeral growth curves in Nothosaurus specimens showing large neonatal sizes and delayed maturity akin to live-bearing squamates, with supporting embryo fossils in closely related pachypleurosaurs suggesting internal gestation rather than egg-laying on land.^[2] A 2024 discovery of a nothosaur vertebra from New Zealand's Balmacaan Formation, dated to approximately 246 million years ago, represents the oldest Southern Hemisphere record and implies early migratory capabilities, with individuals dispersing from northern Tethyan origins to high paleolatitudes (>60° S) via coastal routes shortly after the end-Permian extinction.^[5] This finding challenges prior models of restricted distributions and supports trans-oceanic or circum-Gondwanan movements for accessing distant basins.^[5]

References

[1]
A gigantic nothosaur (Reptilia: Sauropterygia) from the Middle ...
Nov 27, 2014 · Here we report a gigantic nothosaur from the lower Middle Triassic of Luoping in southwest China (eastern Tethyan ocean), which possesses the largest known ...Missing: paleontology | Show results with:paleontology
[2]
Life‐history strategies indicate live‐bearing in Nothosaurus ...
Mar 13, 2019 · The Triassic radiation consists of shallow marine Placodontia, Pachypleurosauria and Nothosauria as well as of the more open marine Pistosauria.
[3]
Article Ancestral body plan and adaptive radiation of sauropterygian ...
Dec 22, 2022 · Sauropterygia is the most diversified and dominant clade among marine reptiles, but their early evolution is scarcely understood.
[4]
Sauropterygian remains from the Middle Triassic of Villány, Hungary ...
Mar 3, 2021 · Sauropterygia was a diverse clade of secondary aquatic reptiles, which represented one of the most important vertebrate groups in the ...<|control11|><|separator|>
[5]
Nothosaur tracks from the Middle Triassic of Spain suggest a global ...
May 30, 2022 · The first marine reptiles are known from the late Early Triassic, including ichthyosaurs, nothosaurs and pachypleurosaurs, while placodonts and ...Missing: sources | Show results with:sources
[6]
The redescription of the holotype of Nothosaurus mirabilis (Diapsida ...
Aug 26, 2022 · It is here interpreted as a radius. It has a convex proximal head; a constricted shaft and the distal end is wider than the shaft but not as ...
[7]
Bone histology, microanatomy, and growth of the nothosauroid ...
Simosaurus was relatively large with a body length of 3 to 4 meters (Rieppel, 1994). Morphological most characteristic is its brevirostrine, blunt and flattened ...
[8]
https://www.sciencedirect.com/science/article/pii/S1631068315000639
[9]
https://www.researchgate.net/publication/237169073_Lariosaurus_xingyiensis_Reptilia_Sauropterygia_from_the_Triassic_of_China
[10]
https://doi.org/10.1371/journal.pone.0158448
[11]
[PDF] comparing Nothosauroidea, Plesiosauria, and Chelonioidea
Some nothosaur taxa display hyperphalangy (Storrs 1993; Rieppel 1998). Overall, the foreflippers are round or paddle-shaped and probably had webbed digits ( ...
[12]
Nothosaurus luopingensis sp. nov. (Sauropterygia) from the Anisian ...
Oct 26, 2022 · Compared with Lariosaurus, the following morphological features of the pectoral girdle and the limbs also support the assignment of the specimen ...<|control11|><|separator|>
[13]
Diverse Aquatic Adaptations in Nothosaurus spp. (Sauropterygia)
Nothosaurus spp. shows a variety of diaphyseal microanatomical patterns, ranging from thick to very thin-walled cortices.Missing: 1998 | Show results with:1998
[14]
Evolutionary implications of the divergent long bone histologies of ...
Jun 18, 2013 · The generally lamellar zonal bone tissue of nothosaur long bones indicates a low growth rate and suggests a low basal metabolic rate.Missing: plan | Show results with:plan
[15]
[PDF] Nothosauroidea from the Vossenveld Formation and their relatives
The hand of Lariosaurus exhibits hyperphalangy (i.e. the condition in which more digital bones are present), as does the foot in specifically Lariosaurus/ ...
[16]
Nothosaurus - Paleofile.com
Genus: Nothosaurus MUNSTER, 1834. Etymology: Greek, nothos, “bastard, illegitimate” and Greek, sauros, “lizard”: Illegitimate lizard.Missing: false | Show results with:false
[17]
Earliest long-necked sauropterygian Lijiangosaurus yongshengensis and plasticity of vertebral evolution in sauropterygian marine reptiles - Communications Biology
- **Definition of Nothosauria**: All taxa more closely related to *Brevicaudosaurus jiyangshanensis*, *Germanosaurus schafferi*, and *Nothosaurus* species than *Keichousaurus hui*, *Simosaurus gaillardoti*, or *Corosaurus alcovensis* (maximum clade definition).
[18]
New highly pachyostotic nothosauroid interpreted as a filter-feeding ...
Aug 1, 2018 · Nothosauria is a well-represented and diverse Eurasian Triassic sauropterygian clade [2]. Its sister group, Simosauridae, is poorly known, only ...
[19]
(PDF) Nothosaurus luopingensis n. sp. (Sauropterygia) from the ...
Jun 2, 2022 · ... hyperphalangy in the manus, and the absence of pachyostosis in the vertebrae and ribs. On the other hand, the specimen possesses some ...
[20]
https://bmcecolevol.biomedcentral.com/articles/10.1186/s12862-023-02150-w
[21]
https://www.researchgate.net/publication/361028271_Nothosaurus_luopingensis_n_sp_Sauropterygia_from_the_Anisian_Middle_Triassic_of_Luoping_Yunnan_Province_China
[22]
https://doi.org/10.7717/peerj.13818
[23]
A new pachypleurosaur (Reptilia: Sauropterygia) from the Middle ...
Jan 5, 2024 · We report a new species of Pachypleurosauria, Dianmeisaurus mutaensis sp. nov., from a recently discovered Lagerstätte in the Upper Member of the Anisian ...Missing: Asian | Show results with:Asian
[24]
Rapid neck elongation in Sauropterygia (Reptilia
Aug 31, 2023 · Comparative phylogenetic analysis shows that neck elongation occurred rapidly in all Triassic eosauropterygian lineages, probably driven by ...Results · Discussion · Ancestral State EstimationMissing: studies | Show results with:studies
[25]
Oldest southern sauropterygian reveals early marine reptile ...
a nothosaur (basal sauropterygian) from the Middle ...
[26]
Early Triassic marine reptile representing the oldest record of ...
Jan 24, 2019 · ... Early Triassic, and challenges the traditional view that the ... On the new nothosaurs from Hupeh and Kweichou, China. Vertebrata ...
[27]
An Early Triassic sauropterygian and associated fauna from South ...
Feb 11, 2020 · Here we report new material of the Early Triassic sauropterygian Lariosaurus sanxiaensis and associated fauna from the Jialingjiang Formation in Hubei Province ...Missing: review | Show results with:review
[28]
Extinction and dawn of the modern world in the Carnian (Late Triassic)
Sep 16, 2020 · The Carnian Pluvial Episode (Late Triassic) was a time of global environmental changes and possibly substantial coeval volcanism.
[29]
The redescription of the holotype of Nothosaurus mirabilis (Diapsida ...
Aug 26, 2022 · The genus Nothosaurus existed during the Middle Triassic (mainly Anisian to Ladinian; one species is known from the early Carnian). Isolated ...Missing: peak | Show results with:peak
[30]
A New Species of the Sauropsid Reptile Nothosaurus from ... - BioOne
Dec 1, 2009 · Table 2. Comparison of skull proportions and dentition in Nothosaurus including Nothosaurus winkelhorsti sp. nov. (NMNHL RGM 443825).
[31]
The first specimen with skin preserved of Lariosaurus ...
Aug 29, 2025 · The specimen here described is the first known nothosaurid with skin preserved all over the body, outlining the entire body profile (Fig. 3).Missing: plan | Show results with:plan
[32]
A gigantic nothosaur (Reptilia: Sauropterygia) from the Middle ...
Nov 27, 2014 · Nothosauroid sauropterygians in general were well adapted to prey on fish and cephalopods, and occasionally, the preservation of rare gastric ...
[33]
(PDF) A new pachypleurosaur (Reptilia: Sauropterygia) from the ...
Here, we report a new species of Pachypleurosauria, Dianmeisaurus mutaensis sp. nov., from a recently discovered Lagerstätte in the Upper Member of the Anisian ...
[34]
https://pmc.ncbi.nlm.nih.gov/articles/PMC4245812/
[35]
Ancient polar sea reptile is the oldest ever found in the Southern ...
Jun 18, 2024 · An Early Triassic Nothosaur fossil vertebra, from about 246 million years ago, discovered in New Zealand has upended long-standing hypotheses.
[36]
Fossil Reptiles from the Panchet Beds of India - Nature
W. E. Swinton's paper1 that nothosaurs are found at widely separated localities along the shores of the ancient sea of Tethys, from Europe eastwards to Japan.
[37]
Taphonomy and palaeobiology of early Middle Triassic coprolites ...
Taphonomy and palaeobiology of early Middle Triassic coprolites from the Luoping biota, southwest China: Implications for reconstruction of fossil food webs.
[38]
(PDF) New information on the dentition and tooth replacement of ...
Aug 6, 2025 · Dental morphology and tooth replacement of Nothosaurus are described and discussed in detail based on two well-preserved specimens of N.
[39]
The locomotory apparatus and paraxial swimming in fossil and living ...
Jun 1, 2021 · Some nothosaur taxa display hyperphalangy (Storrs 1993; Rieppel 1998). Overall, the foreflippers are round or paddle-shaped and probably had ...<|control11|><|separator|>
[40]
Nothosaurus: The Fierce Predators of Ancient Seas - Ocean Info
The Nothosaurus, who descended from terrestrial animals, were fish predators. ... Some of them possessed clawed digits, indicating they could indeed move on land, ...Appearance · Habitat · Faqs
[41]
Nothosaur foraging tracks from the Middle Triassic of southwestern ...
Jun 11, 2014 · The genus name is based on ancientGreek (dikopos), meaning two-oared, a term generally applied to ships rather than marine reptiles. The species ...