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While the holotype of Temnodontosaurus crassimanus still remains on display at the Yorkshire Museum, it has remained largely understudied and the validity of the species has long been questioned. Through re-examination, this study highlights several morphological features of the postcranial skeleton and determines that T. crassimanus is a valid species of the genus and includes several distinct characters that can be used to distinguish it from T. trigonodon, to which it was once assigned. These include a large, robust humerus that is proximodistally longer than the scapula (scapula length vs humerus length ratio: ~0.68); forefins which are significantly longer but less than twice the length of the hindfin (forefin length vs hindfin length ratio: ~1.51); the relative size of the forefins compared with the total body length; along with several other characters that may prove to be unique, such as humerus distal width almost equal to humerus length; presence of notching in at least five leading edge elements of both the fore- and hindfins; and anteroposteriorly wider fore- and hindfins compared with T. trigonodon. Additional specimens, previously tentatively assigned to T. crassimanus, were located and examined, but none could confidently be assigned to the species. [ABSTRACT FROM AUTHOR]

An almost complete ichthyosaur from the historically significant collection of fossils amassed by Somerset geologist, Charles Moore, is described. Available information suggests that it was collected from the Lower Lias of Somerset, UK. However, inspection of the surrounding matrix, which seems to be a nodule, indicates that the specimen may instead hail from the Upper Lias (Toarcian) Strawberry Bank Lagerstätte of Ilminster, Somerset. The specimen had previously been identified as Leptonectes tenuirostris. Herein, further analysis of the skull and forefin, reveals closer affinities to Stenopterygius triscissus, to which the specimen is tentatively assigned. Therefore, the specimen represents one of the most complete ichthyosaurs collected from the Strawberry Bank Lagerstätte. [ABSTRACT FROM AUTHOR]

Numerous specimens of Ichthyosaurus are known, but only very few small examples (total length of <1 m) have been assigned beyond Ichthyosaurus sp. Here, we report on a very small specimen (preflexural length of 560 mm) that can be unequivocally assigned to Ichthyosaurus communis due to possessing a unique combination of diagnostic skull and postcranial characters that are found in larger examples of the species. Furthermore, the specimen is identified as a neonate because of the small size, large sclerotic ring relative to the orbital region, and poorly ossified (highly cancellous) bones of the skull and postcranium. It is not an embryo as it is not preserved within an adult specimen and stomach contents are clearly evident. This is therefore the first neonate Ichthyosaurus communis skeleton to be described. The specimen, in the Lapworth Museum of Geology, University of Birmingham, has no provenance data associated with it. A microfossil analysis of the matrix in which the ichthyosaur skeleton is preserved strongly suggests a stratigraphic range of uppermost Hettangian to lowermost Sinemurian age (Lower Jurassic), but does not provide any geographical information. [ABSTRACT FROM AUTHOR]

Ichthyosaurus communisDe la Beche & Conybeare, 1821 andI. intermediusConybeare, 1822 have been considered synonymous by some researchers, but distinct species by others. The distinction between the two species was originally based on tooth morphology, which has been shown to vary ontogenetically as well as within an individual. Subsequent literature of the nineteenth century did not propose adequate diagnostic features to distinguish the two species. In addition, illustrations suggest that both species were confused withI. breviceps, which was defined over 50 years later. The type specimens of both species are missing, making the problem unresolvable. However, a neotype was designated forI. communisto retain the widely used species name and to stabilize the taxonomy. The species can be recognized by a symmetric, triangular maxilla with long processes and a large, broad, triradiate lacrimal, as well as a unique combination of other characters. The neotype shares numerous features with theI. intermedius ‘type figure’, including the morphologies of the maxilla, prefrontal, lacrimal, jugal and postorbital, such that the two are nearly indistinguishable. ThusI. intermediusmust be considered a synonym ofI. communis.Ichthyosaurus communiscan be identified from the Lyme Regis-Charmouth coast, west Dorset; the ?Whitby coast of Yorkshire; and probably from Street, Somerset. The stratigraphical range ofI. communisis at least lower Hettangian to lower Sinemurian. [ABSTRACT FROM PUBLISHER]

Thousands of ichthyosaurs have been discovered from the rich Lower Jurassic deposits of the UK, with the majority collected from along the Lyme Regis-Charmouth area of the Dorset coast. Here, I describe a new leptonectid ichthyosaur,Wahlisaurus massaraegen. et sp. nov., based on a partial skull and an incomplete skeleton collected from the Lower Jurassic (Hettangian) of Nottinghamshire, England.Wahlisauruscan be referred to the Leptonectidae through the possession of an extremely slender and delicate snout, and a mandible shorter than the snout which produces an overbite. This referral is supported by a phylogenetic analysis. The new taxon is distinguished from other ichthyosaurs through a unique combination of characters and autapomorphies of the pectoral girdle including the presence of both a scapular-coracoid foramen and a large and roughly ovoid coracoid foramen. A coracoid foramen has only previously been reported in the Triassic ichthyosaurCymbospondylus. The peculiar coracoid morphology further highlights the taxonomic utility of coracoids in ichthyosaurs. The aforementioned features demonstrate thatW. massaraecannot be referred to any currently recognized leptonectid.Wahlisaurusis the ninth Lower Jurassic ichthyosaur genus to be recognized worldwide, and the fifth documented in the Lower Lias Group. http://zoobank.org/urn:lsid:zoobank.org:pub:EE500E11-66AB-43C8-BB59-F21654763241 [ABSTRACT FROM AUTHOR]

A 9.7 m long trackway was discovered in a plattenkalk quarry near the village of Wintershof, Bavaria, Germany, in 2002. The huge ichnofossil derives from the Lower Tithonian, Upper Jurassic Solnhofen Lithographic Limestone. The trackway is complete from beginning to end and consists of footprints, telson drag impressions, prosoma imprints and is identified as the ichnotaxon Kouphichnium isp. Preserved at the very end of the trackway is a complete specimen of Mesolimulus walchi confirming the trackway as a mortichnia (death march). Trackways and trace makers preserved together in the fossil record are rare and such specimens allow unique insights into behavior and ecology. The events that led to M. walchi preserved in this sediment are unknown; however, a most likely scenario is that the limulid was washed into the lagoonal environment during a harsh storm. [ABSTRACT FROM AUTHOR]

The validity of the parvipelvian ichthyosaur genusProtoichthyosauruswas evaluated by examining the type material and recently recognized specimens.Protoichthyosaurushas a wide forefin with at least five primary digits, an anterior digital bifurcation in the forefin, a humerus that is nearly equal in width distally and proximally, and a coracoid with well-developed anterior and posterior notches, features it shares with the more common genusIchthyosaurus. Previously,Protoichthyosauruswas synonymized withIchthyosaurusbecause of an incomplete understanding of forefin variation in the latter taxon. However,Protoichthyosaurushas several features in the forefin that distinguishes it fromIchthyosaurus, including the presence of three elements in the distal carpal row, a contact between distal carpal 3 and the ulnare, a bifurcation of distal carpal 2 to form two elements in the metacarpal row, the proximal element of the bifurcation nearly separating distal carpal 2 from distal carpal 3, distal carpal 3 separating the intermedium from contact with distal carpal 4, and the absence of digit V. A phylogenetic analysis confirms thatProtoichthyosaurusis the sister taxon ofIchthyosaurusand is nested in Ichthyosauridae. We recognize two species,P. prostaxalisandP. applebyi, sp. nov., but notP. prosostealis.Protoichthyosaurusis unequivocally from the Hettangian but might be present in the Rhaetian to lower Sinemurian. The genus is geographically widespread across the U.K. http://www.zoobank.org/urn:lsid:zoobank.org:pub:23CA73CE-BB9A-4EAD-81BA-A6D27ABC82CB SUPPLEMENTAL DATA—Supplemental materials are available for this article for free atwww.tandfonline.com/UJVP Citation for this article: Lomax, D. R., J. A. Massare, and R. T. Mistry. 2017. The taxonomic utility of forefin morphology in Lower Jurassic ichthyosaurs:ProtoichthyosaurusandIchthyosaurus. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1361433. [ABSTRACT FROM AUTHOR]

ABSTRACT—Ichthyosaurus conybeariis a rare species, previously known only from an incomplete holotype and one referred specimen, both from the Lyme Regis area of the west Dorset coast, U. K. A newly recognized, nearly complete specimen (NMW 93.5G.2) is the first occurrence of the species in Somerset, U. K. A revised diagnosis recognizes new morphological characters that distinguish the species: slender maxilla with a long, delicate premaxillary process; narrow postorbital; humerus with an anteriorly offset dorsal process that has a well-defined lip extending slightly into the shaft; fibula that is much larger dorsoventrally and mediodistally than tibia; and wide rectangular ischium that is much shorter than the pubis and femur. Notching of anterior fin elements in the forefin had been used as a diagnostic character, but a review of notching withinIchthyosaurussuggests that it has little taxonomic utility. Another specimen (NHMUK R15907), herein referred to the species, extends the range ofI. conybearifrom the upper Hettangian to lower Pliensbachian stages of the Lower Jurassic, the longest duration of any species of the genus. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free atwww.tandfonline.com/UJVP Citation for this article: Massare, J. A., and D. R. Lomax. 2016. A new specimen ofIchthyosaurus conybeari(Reptilia, Ichthyosauria) from Watchet, Somerset, England, U.K., and a reexamination of the species. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1163264. [ABSTRACT FROM PUBLISHER]

We describe a new species of Lower Jurassic (Hettangian/Sinemurian–Pliensbachian) ichthyosaur,Ichthyosaurus anningae, sp. nov., from west Dorset, England, U.K. The holotype ofI. anningae(DONMG:1983.98), at least a subadult, is from the lower Pliensbachian Stonebarrow Marl Member (Charmouth Mudstone Formation). It is the most complete ichthyosaur known from this time interval worldwide. The species is assigned toIchthyosauruson the basis of humerus, forefin, and pectoral girdle morphologies. Diagnostic features of the species include a short, robust humerus with prominent processes; a femur in which the proximal width is almost as large as the distal width; and a very small femur relative to the humerus (humerus/femur ratio >1.7). Four other specimens, at least three of which are juveniles, are referred to this species. The new species may display sexual dimorphism in humeral morphology, but this cannot be confirmed due to a lack of stratigraphic information. With the recognition ofI. anningae, at least three and possibly as many as five ichthyosaur species, representing three genera, are known from the Pliensbachian. http://zoobank.org/urn:lsid:zoobank.org:pub:A5778FB5-A116-480A-93CA-AFC932ACAB55 SUPPLEMENTAL DATA—Supplemental materials are available for this article for free atwww.tandfonline.com/UJVP [ABSTRACT FROM PUBLISHER]