[PaleoOrnithology • 2018] Vorombe gen. nov. • Unexpected Diversity within the Extinct Elephant Birds (Aves: Aepyornithidae) and A New Identity for the World's Largest Bird

Vorombe titan  (Andrews, 1894)

in Hansford & Turvey, 2018 
DOI: 10.1098/rsos.181295  

Illustration: Jaime Chirinos   twitter.com/JamesHansford5

Abstract

Madagascar's now-extinct radiation of large-bodied ratites, the elephant birds (Aepyornithidae), has been subject to little modern research compared to the island's mammalian megafauna and other Late Quaternary giant birds. The family's convoluted and conflicting taxonomic history has hindered accurate interpretation of morphological diversity and has restricted modern research into their evolutionary history, biogeography and ecology. We present a new quantitative analysis of patterns of morphological diversity of aepyornithid skeletal elements, including material from all major global collections of aepyornithid skeletal remains, and constituting the first taxonomic reassessment of the family for over 50 years. Linear morphometric data collected from appendicular limb elements, and including nearly all type specimens, were examined using multivariate cluster analysis and the Bayesian information criterion, and with estimation of missing data using multiple imputation and expectation maximization algorithms. These analyses recover three distinct skeletal morphotypes within the Aepyornithidae. Two of these morphotypes are associated with the type specimens of the existing genera Mullerornis and Aepyornis, and represent small-bodied and medium-bodied aepyornithids, respectively. Aepyornis contains two distinct morphometric subgroups, which are identified as the largely allopatric species A. hildebrandti and A. maximus. The third morphotype, which has not previously been recognized as a distinct genus, is described as the novel taxon Vorombe titan. Vorombe represents the largest-bodied aepyornithid and is the world's largest bird, with a mean body mass of almost 650 kg. This new taxonomic framework for the Aepyornithidae provides an important new baseline for future studies of avian evolution and the Quaternary ecology of Madagascar.

 Systematic Palaeontology

Order Struthioniformes Latham, 1790 

Family Aepyornithidae Bonaparte, 1853 

Genus Aepyornis Geoffroy Saint-Hilaire, 1851 

Aepiornis Geoffroy Saint-Hilaire, 1851, p. 52 

Epiornis Muller and Baldamus, 1851, p. 48 

Epyornis Bonaparte, 1853, p. 139 

Type species: Aepyornis maximus Geoffroy Saint-Hilaire, 1851 (by monotypy).

Recognized species: Aepyornis maximus Geoffroy Saint-Hilaire, 1851; Aepyornis hildebrandti Burckhardt, 1893

.....

Genus Mullerornis Milne-Edwards and Grandidier, 1894

Flacourtia Andrews, 1895, p 23 

Type species: Mullerornis betsilei Milne-Edwards and Grandidier, 1894; designated by Richmond.

Recognized species: Mullerornis modestus (Milne-Edwards and Grandidier, 1869)

 Vorombe titan (Andrews, 1894)

Illustration: Jaime Chirinos 

Genus Vorombe gen. nov.

Etymology: From the Malagasy for ‘big bird’ (neuter).

Type species: Aepyornis titan Andrews, 1894

 Vorombe titan (Andrews, 1894)

Aepyornis titan Andrews 1894, p. 18 

Aepyornis ingens Milne-Edwards and Grandidier, 1894, p. 124

Figure 7.  Vorombe titan , femur (NHMUK A439), Itampolo (Itampulu Vé), Madagascar; part of syntype series.

   

James P. Hansford and Samuel T. Turvey. 2018. Unexpected Diversity within the Extinct Elephant Birds (Aves: Aepyornithidae) and A New Identity for the World's Largest Bird. Royal Society Open Science. DOI: 10.1098/rsos.181295

After decades of conflicting evidence, scientists at @ZSLScience have put the ‘world’s largest bird’ debate to rest. The extinct Vorombe titan has taken the title at over 3 metres tall and weighing up to 800kg:   zsl.org/science/news/zsl-names-world’s-largest-ever-bird-–-vorombe-titan … #elephantbirds #birds  

twitter.com/JamesHansford5/status/1044870794063618049

Team names world's largest ever bird—Vorombe titan  phys.org/news/2018-09-team-world-largest-birdvorombe-titan.html via @physorg_com

[PaleoMammalogy • 2018] Nanodobenus arandai • A Dwarf Walrus from the Miocene of Baja California Sur, Mexico

Nanodobenus arandai 

Velez-Juarbe & Salinas-Márquez, 2018

 DOI: 10.1098/rsos.180423 

twitter.com/VelezJuarbeJ

Abstract

Here, we describe the odobenid Nanodobenus arandai gen. et sp. nov., based on a nearly complete left mandible from the mid to late Miocene Tortugas Formation in Baja California Sur. Nanodobenus is distinguished among odobenids by displaying a unique combination of plesiomorphic and derived characters, such as narrow mandibular symphysis, well-developed genial tuberosity, bilobed canine and p2 roots, bulbous post-canine teeth with the paraconid, protoconid and hypoconid, and smooth lingual cingula. Moreover, it is characterized by its small adult body length, which is estimated at about 1.65 m. Throughout the Miocene–Pliocene odobenids are characterized by an increase in body size, especially after the extinction of desmatophocids in the late Miocene. The small size of Nanodobenus departs from this trend, demonstrating that there was greater size disparity among odobenids in the mid–late Miocene than previously thought. It is hypothesized that Nanodobenus occupied a niche that was later on occupied by similar-sized otariids, such as Thalassoleon mexicanus, which occurs sympatrically with large odobenids in the overlying Almejas Formation.

KEYWORDS: Odobenidae, marine mammals, eastern Pacific, Miocene

Systematic palaeontology

Pinnipedia Illiger, 1811

Odobenidae Allen, 1880

Nanodobenus arandai, gen. et sp. nov.

Etymology. The name derives from the combination of ‘nano’, from the Latin ‘nanus’ which translates to dwarf, in reference to the small size of the specimen and estimated body size, combined with Odobenus, the genus of extant walrus, Odobenus rosmarus (Linnaeus, 1758), and the occasionally used suffix in odobenids (e.g. Archaeodobenus). The specific epithet honours Dr Francisco Aranda-Manteca (UABC) in recognition of his mentorship to the junior author and contributions to the knowledge of extinct marine vertebrates of Baja California and Baja California Sur.

Holotype. UABC FCM 0072, nearly complete left mandible, including p2–4. Collected by T. McMillan, c. 1987.

Type locality. Arroyo La Chiva (=Arroyo Tiburón [12–14]), Asunción, Baja California Sur, Mexico (figure 1).

Figure 2. Mandible and lower dentition of Nanodobenus arandai gen. et sp. nov. (UABC FCM 0072).

Mandible in lateral (a), medial (b) and occlusal (c) views. Lower dentition in labial (d), lingual (e) and occlusal (f) views. 

Abbreviations: c, lower canine; di, digastric insertion; gt, genial tuberosity; hyd, hypoconid; lc, lingual cingulum; p1–4, lower premolars 1–4; m1–2, lower molars 1–2; maf, masseteric fossa; mf, mental foramina; mnf, mandibular foramen; ms, mandibular sumphysis; pad, paraconid; prd, protoconid; wf, wear facet.

Figure 4. Time-calibrated strict consensus tree of Odobenidae and body size distribution.

Species range from [Velez-Juarbe, 2017; Boessenecker & Churchill, 2018; Boessenecher et al., 2018]; body size estimates from table 3 and outlines modified from Berta et al. [2018] and Lydersen [2018]. Numbers in nodes represent posterior probability (in bold) and bootstrap values.

Jorge Velez-Juarbe and Fernando M. Salinas-Márquez. 2018. A Dwarf Walrus from the Miocene of Baja California Sur, Mexico. Royal Society Open Science. DOI: 10.1098/rsos.180423

twitter.com/VelezJuarbeJ/status/1027207623593078784

[Paleontology • 2018] Primitivus manduriensis • A New Fossil Marine Lizard with Soft Tissues from the Late Cretaceous of southern Italy

Primitivus manduriensis 

Paparella, Palci, Nicosia & Caldwell, 2018

   DOI:  10.1098/rsos.172411 

Abstract

A new marine lizard showing exceptional soft tissue preservation was found in Late Cretaceous deposits of the Apulian Platform (Puglia, Italy). Primitivus manduriensis gen. et sp. nov. is not only the first evidence of the presence of dolichosaurs in a southern Italian Carbonate Platform, filling a palaeogeographic gap in the Mediterranean Tethys, but also extends the range of this group to the upper Campanian–lower Maastrichtian. Our parsimony analysis recovers a monophyletic non-ophidian pythonomorph clade, including Tetrapodophis amplectus at the stem of Mosasauroidea + Dolichosauridae, which together represent the sister group of Ophidia (modern and fossil snakes). Based on Bayesian inference instead, Pythonomorpha is monophyletic, with Ophidia representing the more deeply nested clade, and the new taxon as basal to all other pythonomorphs. Primitivus displays a fairly conservative morphology in terms of both axial elongation of the trunk and limb reduction, and the coexistence of aquatic adaptations with features hinting at the retention of the ability to move on land suggests a semi-aquatic lifestyle. The exceptional preservation of mineralized muscles, portions of the integument, cartilages and gut content provides unique sources of information about this extinct group of lizards. The new specimen may represent local persistence of a relict dolichosaur population until almost the end of the Cretaceous in the Mediterranean Tethys, and demonstrates the incompleteness of our knowledge of dolichosaur temporal and spatial distributions.

KEYWORDS: Squamata, Pythonomorpha, Apulian Platform, Cretaceous, soft tissue, ultraviolet radiation

Figure 1. Holotype of Primitivus manduriensis gen. et sp. nov. (MPUR NS 161) at natural (a) and UV (b) light as exposed from the matrix in dorsal view. The imaging under UV radiations is a composite of two pictures. Scale bars: 5 cm. 

 Systematic palaeontology

Reptilia Linnaeus, 1758

Squamata Oppel, 1811

Pythonomorpha Cope, 1869

DOLICHOSAURIDAE Gervais, 1852

Definition. Dolichosauridae is here defined as the group including all taxa sharing a more recent common ancestor with Dolichosaurus longicollis than with Aigialosaurus sp. In our study, this includes the following genera: Dolichosaurus, Pontosaurus, Primitivus gen. nov., Adriosaurus, Acteosaurus, and Aphanizocnemus (cf. Nopcsa [1903] and Conrad [2008]).

Diagnosis. Dolichosauridae is here defined as the group of non-ophidian pythonomorphs characterized by the following combination of features: non-sutural contact between premaxilla and maxilla; jugal lacking large posterior process; postorbital portion of postfrontal + postorbital forming half or more of the posterior orbital margin; hypapophyses/hypapophyseal peduncles extending to the tenth presacral/precloacal vertebra or beyond (10–12 cervical vertebrae); 32–40 presacral/precloacal vertebrae; reduced scapula and coracoid; tail deep, laterally compressed (cf. Pierce & Caldwell [2004], Caldwell [2006,2000], Palci & Caldwell [2010]).

Primitivus manduriensis gen. et sp. nov.

Etymology. The genus is named after the famous red wine grape variety, ‘Primitivo’, native to and grown in great quantities in the Salento Peninsula (Puglia, southern Italy). The species name has been chosen to honour the full name of the wine, ‘Primitivo di Manduria’, which is not only produced around the town of Manduria (Taranto, Puglia), but also in other localities of the Salento Peninsula, including Nardò, where the specimen was found.

Holotype. MPUR NS 161, an almost complete skeleton mostly in articulation, exposed in dorsal view, partially embedded in the rock, and missing the terminal portion of the tail and some elements of the skull. Together with the skeleton, there are abundant soft tissues preserved, including permineralized muscle fibres and integument. 

Locality and stratigraphy. Nardò, Lecce (Puglia, southern Italy); higher portion of the informal geological unit ‘Calcari di Melissano’, Apulian Carbonate Platform.

Age. Upper Campanian–lower Maastrichtian, based on microfossils.

Diagnosis. The new taxon can be distinguished from other dolichosaurids by the following unique combination of features: contact between frontal and prefrontal limited in the dorsal view; sutural contact between the septomaxilla anterolateral margin and the maxilla; the septomaxilla posterolateral margin in contact with the nasal; 10 cervical vertebrae + 22 dorsal vertebrae (32 presacrals); bowtie-shaped astragalus (with both a dorsal and a ventral notch); calcaneum with a proximal concavity for articulation with the fibula; deeply imbricated, small sub-circular scales on the lateral sides of the trunk and limbs; larger diamond-shaped scales on the trunk dorsal region; transversally expanded subcaudal scales.

Figure 12. Primitivus manduriensis three-dimensional model and life reconstruction. The specimen is preserved in sediments deposited in the shallower portion of an inner lagoon of the Apulian Carbonate Platform, and is inferred to have a semi-aquatic lifestyle. Three-dimensional model (a) and life reconstruction (b) created by Fabio Manucci.

Ilaria Paparella, Alessandro Palci, Umberto Nicosia and Michael W. Caldwell. 2018. A New Fossil Marine Lizard with Soft Tissues from the Late Cretaceous of southern Italy.  Royal Society Open Science.   DOI:  10.1098/rsos.172411

[PaleoMammalogy • 2018] Macrosqualodelphis ukupachai • A New Large Squalodelphinid (Cetacea, Odontoceti) from Peru Sheds Light on the Early Miocene Platanistoid Disparity and Ecology

Macrosqualodelphis ukupachai  

Bianucci, Bosio, Malinverno, de Muizon, Villa, Urbina & Lambert, 2018

   DOI: 10.1098/rsos.172302 

Abstract

The South Asian river dolphin (Platanista gangetica) is the only extant survivor of the large clade Platanistoidea, having a well-diversified fossil record from the Late Oligocene to the Middle Miocene. Based on a partial skeleton collected from the Chilcatay Formation (Chilcatay Fm; southern coast of Peru), we report here a new squalodelphinid genus and species, Macrosqualodelphis ukupachai. A volcanic ash layer, sampled near the fossil, yielded the 40Ar/39Ar age of 18.78 ± 0.08 Ma (Burdigalian, Early Miocene). The phylogenetic analysis places Macrosqualodelphis as the earliest branching squalodelphinid. Combined with several cranial and dental features, the large body size (estimated body length of 3.5 m) of this odontocete suggests that it consumed larger prey than the other members of its family. Together with Huaridelphis raimondii and Notocetus vanbenedeni, both also found in the Chilcatay Fm, this new squalodelphinid further demonstrates the peculiar local diversity of the family along the southeastern Pacific coast, possibly related to their partition into different dietary niches. At a wider geographical scale, the morphological and ecological diversity of squalodelphinids confirms the major role played by platanistoids during the Early Miocene radiation of crown odontocetes.

KEYWORDS: Odontoceti, Squalodelphinidae, Early Miocene, Peru, phylogeny, palaeoecology

Systematic palaeontology

Cetacea Brisson, 1762

Neoceti Fordyce and Muizon, 2001

Odontoceti Flower, 1867

Platanistoidea Gray, 1863

Squalodelphinidae Dal Piaz, 1917

Type genus. Squalodelphis Dal Piaz, 1917

Other genera included. Huaridelphis, Medocinia, Notocetus, Phocageneus.

Macrosqualodelphis, gen. nov.

Etymology. From ‘Macro’, large, and ‘Squalodelphis’ the type genus of the family. Gender masculine.

Macrosqualodelphis ukupachai, sp. nov.

Holotype and only referred specimen. MUSM 2545 consists of a skull lacking the anterior portion of the rostrum, the ear bones, both mandibles and the hyoid bones. The ventralmost portion of the rostrum and of the basicranium is worn along a plane slightly anterodorsally sloping with respect to the horizontal plane of the skull (erupted portion of maxillary teeth, basioccipital crests, ventral part of exoccipitals and postglenoid processes of squamosals missing). MUSM 2545 also preserves three detached anterior teeth; the atlas, two thoracic, two lumbar and eight caudal vertebrae; the left humerus, radius and incomplete ulna; one phalanx and one metacarpal; and two small fragments of ribs.

Type locality. About 3 km south of the fossiliferous Cerro Colorado locality, Western Ica Valley, Ica Region, southern Peru. 710 m above sea level. The holotype was discovered and collected by one of the authors (M.U.).

Etymology. From ‘Uku Pacha’ (Uku = within, inside; Pacha = Earth), the Inca lower world, located below the Earth's surface, in reference to the discovery of the specimen buried in sediment.

Figure 16. Skeletal remains and inferred body outline of the squalodelphinids from the early Burdigalian of the Chilcatay Fm (Pisco Basin, Peru) and skeletal and body outline of the extant P. gangetica. Body lengths based on the Pyenson & Sponberg [2011] equation for the fossils and on Jefferson et al. [2008] for the extant P. gangetica.


Cranium of the holotype (MUSM 2545) of Macrosqualodelphis ukupachai, from the early Burdigalian of the Chilcatay Fm (Pisco Basin, Peru).

Figure 3. (a) Dorsal view; (b) corresponding explanatory line drawing;   Linear hatching indicates major breaks and cross-hatching areas covered by the sediment.

Figure 4. (a) Ventral view; (b) corresponding explanatory line drawing;  Linear hatching indicates major breaks, cross-hatching areas covered by the sediment and dark shading worn surface.

Figure 5. (a) Right lateral view; (b) corresponding explanatory line drawing; (c) left lateral view. Cross-hatching indicates supporting frame.

Conclusion: 

Macrosqualodelphis ukupachai is a new species of the extinct platanistoid family Squalodelphinidae based on a well-preserved partial skeleton collected from the Early Miocene (ca 19–18 Ma) fossiliferous beds of the Chilcatay Fm outcropping in the Western Ica Valley (southern coast of Peru). The age of this skeleton is further constrained via 40Ar/39Ar dating of a local volcanic ash layer to 18.78 ± 0.08 Ma (early Burdigalian).

Our phylogenetic analysis supports the referral of M. ukupachai to the monophyletic family Squalodelphinidae, of which it constitutes the earliest diverging lineage.

The main distinctive character of M. ukupachai is its large size: its estimated TBL is approximately 3.5 m, significantly larger than all other known squalodelphinids, including N. vanbenedeni (2.5 m) and H. raimondii (2.0 m), both also found in the Chilcatay Fm. Combined with cranial and dental features (robust rostrum less tapered than in other squalodelphinids, large temporal fossa, prominent nuchal and temporal crests, and more robust teeth), the large body size of M. ukupachai suggests that this squalodelphinid was able to prey upon larger prey items. Consequently, M. ukupachai would have been positioned higher along the local trophic chain than the roughly contemporaneous N. vanbenedeni and H. raimondii. Therefore, it is suggested that the squalodelphinid diversity, both locally and worldwide, could be related to their partition into different dietary niches, as is observed in the extant delphinids.

This new record further illustrates the first, Early Miocene, broad radiation of crown odontocetes in marine environments, with a major contribution of homodont platanistoids. This Early Miocene morphological and ecological diversification of platanistoids (including squalodelphinids) was followed by the radiation of delphinidans (porpoises, true dolphins and relatives) during the Middle–Late Miocene. The only extant survivor of the platanistoid ‘golden age’ is the endangered South Asian river dolphin P. gangetica, confined in freshwater ecosystems of the Ganges, Indus and Brahmaputra river basins.

Giovanni Bianucci, Giulia Bosio, Elisa Malinverno, Christian de Muizon, Igor M. Villa, Mario Urbina and Olivier Lambert. 2018. A New Large Squalodelphinid (Cetacea, Odontoceti) from Peru Sheds Light on the Early Miocene Platanistoid Disparity and Ecology. Royal Society Open Science. 5(4)  DOI: 10.1098/rsos.172302

 twitter.com/CoastalPaleo/status/986650946942980096

[PaleoMammalogy • 2018] Toipahautea waitaki • A New Archaic Baleen Whale (early-Late Oligocene, New Zealand) and the Origins of Crown Mysticeti

Toipahautea waitaki   Tsai & Fordyce, 2018

Burial in the ancient sea of Zealandia: a Toipahautea whale skeleton is slowly covered by sand 27-28 million years ago, on its path to becoming a fossil 

 Reconstruction by Chris Gaskin, Geology Museum, University of Otago 

DOI: 10.1098/rsos.172453

A new genus and species of extinct baleen whale, †Toipahautea waitaki (Late Oligocene, New Zealand) is based on a skull and associated bones, from the lower Kokoamu Greensand, about 27.5 Ma (local upper Whaingaroan Stage, early Chattian). The upper jaw includes a thin, elongate and apparently toothless maxilla, with evidence of arterial supply for baleen. Open sutures with the premaxilla suggest a flexible (kinetic) upper jaw. The blowhole is well forward. The mandible is bowed laterally and slightly dorsally; unlike the Eomysticetidae, there are no mandibular alveoli, and the coronoid process is tapered and curved laterally. Jaw structure is consistent with baleen-assisted gulp-feeding. The age of early Chattian makes †Toipahautea a very early, if not the oldest named, toothless and baleen-bearing mysticete, suggesting that the full transition from toothed to baleen-bearing probably occurred in the Early Oligocene. Late Oligocene mysticetes vary considerably in jaw form and kinesis, tooth form and function, and development of baleen, implying a wide range of raptorial, suctorial and filter-feeding behaviour. More study may elucidate the function of jaws, teeth and baleen in terms of opportunist/generalist feeding, as in modern gray whales, versus specialized feeding. We here propose that early mysticetes, when transitioned from toothed to baleen-bearing, were generalists and opportunists instead of specializing in any forms of feeding strategies. In addition, two different phylogenetic analyses placed †Toipahautea either in a polytomy including crown Mysticeti, or immediately basal to the crown, and above †Eomysticetidae in both cases. Because the †Toipahautea waitaki holotype is an immature individual, it may plot more basally in phylogeny than its true position.

Keywords: Cetacea, mysticete, feeding strategy, filter-feeding, specialist/generalist, opportunist

  initial preparation of †Toipahautea waitaki OU 21981 by A. Grebneff

 (photo: R.E. Fordyce)

Burial in the ancient sea of Zealandia: a Toipahautea whale skeleton is slowly covered by sand 27-28 million years ago, on its path to becoming a fossil

 Reconstruction by Chris Gaskin, Geology Museum, University of Otago 

Cetacea Brisson, 1762
Mysticeti Gray, 1864

Incertae familiae

Toipahautea waitaki gen. et. sp. nov 

Etymology. Toi means origin and pahautea refers to whalebone/baleen in Maori, alluding to the origin of the early toothless and baleen-bearing mysticetes. Waitaki is a name for the wider region, including the Waitaki River (wai, water or river; taki, tears) into which the smaller Hakataramea River drains.

 Holotype. †Toipahautea waitaki is known only from the holotype, OU 21981: a disarticulated partial skull (parts of the maxillae and premaxillae, left nasal, frontals, squamosals, exoccipitals, basioccipital and supraoccipital), incomplete mandibles, left tympanic bulla and periotic, hyoid(?), atlas, axis, two thoracic vertebrae, two scapulae, a partial humerus, two radii and ribs. Most of the elements were disarticulated but associated when excavated.

Diagnosis. †Toipahautea waitaki is interpreted as a chaeomysticete based on the presence of ‘baleen’ sulci on the ventral surface of the maxilla and lack of mandibular alveoli. †Toipahautea waitaki has a unique combination of: massive size of periotic; well-developed superior process of the periotic; prominent elongation of dorsomedial margin of the internal acoustic meatus; prominent fissure between the fenestra rotunda and the aperture for the cochlear aqueduct; small medial posterior sulcus; the presence of the anteroexternal foramen; the presence of the sigmoidal cavity; the presence of the elliptical foramen; horizontal sigmoidal cleft far anterior than the anterior margin of the sigmoidal process; posteromedial margin of the bulla orienting slightly anteromedially.

Locality and horizon. OU 21981 (field number REF-28.1.88.2) was recovered from the Hakataramea Valley, South Canterbury, South Island, New Zealand (figure 1). ....

....

Cheng-Hsiu Tsai and R. Ewan Fordyce. 2018. A New Archaic Baleen Whale,Toipahautea waitaki (early-Late Oligocene, New Zealand) and the Origins of Crown Mysticeti.   R. Soc. Open Sci. 5: 172453.  DOI: 10.1098/rsos.172453

Whale of a find  odt.co.nz/news/national/whale-find

 scimex.org/newsfeed/oldest-baleen-whale-uncovered-in-new-zealand

 scimex.org/__data/assets/file/0016/316132/Baleen-whale_RSOS_paper.pdf

Whale of a discovery: NZ's ancient (and extinct) ocean mammal, via @nzherald nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=12034869

[Paleontology • 2018] Yunnanechinus luopingensis • A New Stem Group Echinoid from the Triassic of China leads to A Revised Macroevolutionary History of Echinoids during the end-Permian Mass Extinction

Yunnanechinus luopingensis

Thompson, Hu, Zhang, Petsios, Cotton, Huang, Zhou, Wen & Bottjer, 2018

 DOI: 10.1098/rsos.171548 

Abstract

The Permian–Triassic bottleneck has long been thought to have drastically altered the course of echinoid evolution, with the extinction of the entire echinoid stem group having taken place during the end-Permian mass extinction. The Early Triassic fossil record of echinoids is, however, sparse, and new fossils are paving the way for a revised interpretation of the evolutionary history of echinoids during the Permian–Triassic crisis and Early Mesozoic. A new species of echinoid, Yunnanechinus luopingensis n. sp. recovered from the Middle Triassic (Anisian) Luoping Biota fossil Lagerstätte of South China, displays morphologies that are not characteristic of the echinoid crown group. We have used phylogenetic analyses to further demonstrate that Yunnanechinus is not a member of the echinoid crown group. Thus a clade of stem group echinoids survived into the Middle Triassic, enduring the global crisis that characterized the end-Permian and Early Triassic. Therefore, stem group echinoids did not go extinct during the Palaeozoic, as previously thought, and appear to have coexisted with the echinoid crown group for at least 23 million years. Stem group echinoids thus exhibited the Lazarus effect during the latest Permian and Early Triassic, while crown group echinoids did not.

KEYWORDS: sea urchin, Triassic, Lazarus effect, echinoderm, Luoping Biota

Figure 1. Specimens and location of Yunnanechinus luopingensis n. sp.
(a) Locality map showing the location of the Luoping Biota marked as star.
(b) specimen 61701; note the bulge in the centre of the test which probably indicates the Aristotle's lantern inside of the compressed test. (c) Specimen 32321 which shows an apical view of a compressed test with apical disc with genital plates, an ocular plate and the madreporite. (d) Specimen 61163 showing a compressed test with spines. (e) Close-up of spines and ambulacral plate on specimen 32321. Note the absence of a milled ring and the striate nature of the spines. (f) Close-up view of the madreporite, ocular plate and adapical coronal plating of specimen 32321. Note the imbrication of the plates, with more adoral plating imbricating over more adapical plates. (g) Close-up of coronal plating and spines on specimen 32321. Spines and tubercles are arranged in distinct rows with larger spines lying slightly below corresponding imperforate and non-crenulate tubercles.

Scale bars in (b,d) are 1 cm, bar in (c) is 2 mm and bars in (e–g) are 500 µm.

Systematic palaeontology

Echinoidea Leske, 1778

Stem group Echinoidea

Incertae familiae

Genus Yunnanechinus n. gen.

Etymology. Named for Yunnan, China from whence the type species is known.

Type species. Yunnanechinus luopingensis n. sp.

Yunnanechinus luopingensis n. sp.

Etymology. Named for the Luoping Biota, the fossil Lagerstätte from which the species is described.

Diagnosis. Test with imbricate plating, at least adapically and ambitally. Genital plates with one gonopore per plate (figure 1f). Plates of apical system covered with small, imperforate non-crenulate tubercles. Interambulacral plates polygonal to subpentagonal in shape. Interambulacral plates with a single imperforate non-crenulate tubercle, and sparse imperforate non-crenulate secondary tubercles. Spines less than half the diameter of the test in length, finely striate and without a milled ring (figure 1e,g).

Material. The holotype is specimen LPI-32321, paratypes are specimens LPI-2638, LPI-61163, and LPI-61701A,B.

Occurrence. All specimens from the Middle Anisian (Pelsonian) Guanling Formation of the Luoping Biota of Yunnan Province, South China.

Jeffrey R. Thompson, Shi-xue Hu, Qi-Yue Zhang, Elizabeth Petsios, Laura J. Cotton, Jin-Yuan Huang, Chang-yong Zhou, Wen Wen and David J. Bottjer. 2018. A New Stem Group Echinoid from the Triassic of China leads to A Revised Macroevolutionary History of Echinoids during the end-Permian Mass Extinction. ROYAL SOCIETY OPEN SCIENCE. DOI: 10.1098/rsos.171548

  

For #FossilFriday here's Yunnanechinus luopingensis from our paper that came out earlier this week. The #phylogenetic placement of this species indicates that a lineage of the stem group #seaurchins, which were diverse in the #Palaeozoic Era, actually survived into the #Mesozoic! 

 twitter.com/senorjefe33/status/959540124403974144

[Paleontology • 2017] Vadasaurus herzogi • A New Rhynchocephalian (Reptilia: Lepidosauria) from the Late Jurassic of Solnhofen (Germany) and the Origin of the Marine Pleurosauridae

Vadasaurus herzogi

 Bever & Norell, 2017

DOI:  10.1098/rsos.170570  

Abstract

A new rhynchocephalian is described based on a recently discovered and well-preserved specimen from the Late Jurassic (Kimmeridgian) marine limestones of Solnhofen, Bavaria. Phylogenetic analysis recovers the new taxon as the sister group to Pleurosauridae, a small radiation of rhynchocephalians representing the oldest marine invasion of crown-clade Lepidosauria. The relatively strong evidence for this taxonomically exclusive lineage, within a generally volatile rhynchocephalian tree, places the new taxon in a position to inform the early history of the pleurosaur transition to the sea. The early steps in this transition are distributed throughout the skeleton and appear to increase hydrodynamic efficiency for both swimming and aquatic feeding. This early history may also have included a global truncation of plesiomorphic ontogenetic trajectories that left a number of skeletal features with reduced levels of ossification/fusion. The exact degree to which Vadasaurus had adopted an aquatic ecology remains unclear, but the insight it provides into the origin of the enigmatic pleurosaurs exemplifies the potential of Rhynchocephalia for generating and informing broad-based questions regarding the interplay of development, morphology, ecology and macroevolutionary patterns.

KEYWORDS: Bavaria, marine reptile, secondarily aquatic, skeletal development, sphenodon, tiatethys

Figure 1. Holotype of Vadasaurus herzogi (AMNH FARB 32768) collected from the Late Jurassic marine limestones of Solnhofen, Bavaria. The skull, forelimbs, and first 18 presacral vertebrae and ribs are exposed in the dorsal or dorsolateral view. Posteriorly, the skeleton is rotated approximately 180°, making it visible largely in the ventral view. Left hindlimb is exposed in the dorsal view.

Anatomical abbreviations: As, astragalus; Ca, calcaneum; Cdv, caudal vertebra; Co, coracoid; Cr, cervical rib; Cv, cervical vertebra; D, dentary; Dv, dorsal vertebra; F, femur; Fb, fibula; Fr, frontal; Ga, gastralia; H, humerus; I, intermedium; Is, ischium; l, left; Mc, metacarpal; Mt, metatarsal; Mx, maxilla; Ph, phalanx; Pu, pubis; R, radius; r, right; S, scapula; Sc, sternal cartilage; Ss, suprascapular cartilage; Sv, sacral vertebra; T, tibia; U, ulna.

Figure 2. The skull of Vadasaurus herzogi (AMNH FARB 32768). Photographs in the dorsolateral (a) and lateral (b) views; labelled line drawing in the dorsolateral view (c); reconstructions of lateral and dorsal views (d).

Anatomical abbreviations: An, angular; Ar, articular; cp, cultriform process; Cv, cervical vertebra; D, dentary; dd, dentary dentition; Ecp, ectopterygoid; Ept, epipterygoid; exn, external naris; Fr, frontal; Hy, hyobranchial element; if, incisiform fang; Ju, jugal; mf, mandibular foramen; Mx, maxilla; Na, nasal; Pa, parietal; Pal, palatine; paf, parietal foramen; Pf, prefrontal; Pm, premaxilla; Po, postorbital; Pof, postfrontal; Pr, prootic; Pra, prearticular; Pt, pterygoid; Q, quadrate; Qj, quadratojugal; Sa, surangular; sof, suborbital fenestra; Sq, squamosal; Vo, vomer.

Systematic palaeontology

Lepidosauria Haekel, 1866 

Rhynchocephalia Günther, 1867 

Vadasaurus herzogi gen. et sp. no.

  Etymology: Generic name from the Latin vadare ‘to go forth’, which is also the root of ‘to wade’—refers to the taxon's hypothesized phylogenetic position near the proximal end of a terrestrial-to-marine transformation series that produced the aquatic pleurosaurs—and saurus ‘lizard’. The specific epithet honours the celebrated Bavarian film-maker Werner Herzog for his continuing exploration of the relationship between life and time.

Holotype: AMNH FARB 32768, a nearly complete and largely articulated skeleton (figures 1–3). Like most specimens preserved in lithographic limestone, it exhibits compressional effects that include the flattening and shearing of composite structures and the slight displacement of certain elements. Individual bones, however, are preserved largely in three dimensions.

Gabriel S. Bever and Mark A. Norell. 2017. A New Rhynchocephalian (Reptilia: Lepidosauria) from the Late Jurassic of Solnhofen (Germany) and the Origin of the Marine Pleurosauridae.  Royal Society Open Science. 4(11):170570  DOI:  10.1098/rsos.170570 

ResearchGate.net/publication/320928771_A_new_rhynchocephalian_Reptilia_Lepidosauria_from_the_Late_Jurassic_of_Solnhofen_Germany_and_the_origin_of_the_marine_Pleurosauridae

 The fossil was recovered from Kimmeridgian-aged (a subdivision of the Late Jurrasic) marine limestones in the Solnhofen municipality of Bavaria, Germany. They belong to an up until now unknown species dubbed Vadasaurus herzogi, and belongs to the Rhynchocephalia lizard order, a close relative of a small group of ancient reptiles called pleourosaurs (genus Pleurosaurus).

Fossilized ancient lizard shows how dinos evolved to live in the oceans 

zmescience.com/science/ancient-lizard-dino-evolve-ocean-0432/ @zmescience

[Herpetology • 2017] Cyrtodactylus tanim • Morphological and Genetic Evidence for A New Karst Specialist Lizard from New Guinea (Cyrtodactylus: Gekkonidae)

Cyrtodactylus tanim 

 Nielsen & Oliver, 2017 

DOI: 10.1098/rsos.170781 

Abstract

Exposed limestone karst landscapes, especially in the tropics, are often home to distinctive and specialized biotas. Among vertebrates, a particularly large number of karst-associated lizard taxa have been described, but for the vast majority, evidence of specific adaptions to karst is lacking. A number of studies, however, have provided evidence of consistent morphological trends in lizards that use complex, three-dimensional, saxicoline habitats such as those that typify karst areas. Here we combine morphological and genetic data to test whether a newly discovered gecko from an extremely rugged karst area in New Guinea shows morphological trends matching those observed in other lizards associated with complex rock habitats such as karst and caves. Consistent with predictions, the new species' head is flatter and narrower than similar-sized relatives, and it has proportionally larger eyes and longer limbs. These trends indicate this taxon represents the second documented instance of karst specialization in a New Guinean vertebrate, and suggest morphological traits to test for evidence of specialized ecological associations in the many karst-associated Cyrtodactylus taxa from Southeast Asia.

KEYWORDS: Cyrtodactylus, ecological diversity, gecko, morphometric analysis, specialization

Figure 7. Cyrtodactylus tanim n. sp. in life. Paratypes SJR14637 (a,b) and NMV75961 (c) displaying juvenile coloration.

Photographs: Paul M. Oliver. 

Cyrtodactylus tanim n. sp.  

 Diagnosis: Cyrtodactylus tanim n. sp. can be distinguished from all other Melanesian and (Wallacean) Cyrtodactylus by the following unique combination of characters: moderate size (SVL to 96.7 mm) and slender, with a relatively narrow head (HW/SVL 0.17–0.19), mid-dorsal tubercles in 14–16 longitudinal rows at midpoint of body, ventrolateral fold without enlarged tubercles, subcaudal scales not transversely widened, pores in a tripartite series, precloacal pores obvious and of moderate number (15–17), femoral pores minute and numerous (31–30 per limb, 66–76 total), and dorsal colour pattern on torso consisting of six to nine semi-distinctly defined, alternating dark-brown bands or blotches, on a medium-brown background.

Distribution and natural history: Currently known from three sites spanning an elevation from approximately 540 to 1075 m.a.s.l. in near-impenetrable limestone country just east of Kaiangabip Village, Western Province, Papua New Guinea. Similar limestone country is widespread, but difficult to access, along the southern edge of the Central Cordillera, and this species is likely to have a wider range than is currently known.

A similar, moderately sized Cyrtodactylus with many dark-brown dorsal bands was seen—but not collected—in limestone areas in the north of Gulf Province. If this is also Cyrtodactylus tanim n. sp., then it will have a range spanning over 300 km.

Cyrtodactylus tanim n. sp. was collected in hill forest and lower montane forest where it was quite common, especially at higher elevations. Along a ridge of lower montane forest at approximately 1100 m.a.s.l. (figure 8), up to 10 specimens could reliably be seen over several hours of spotlighting on a single night. They were most commonly seen perched at relatively low heights (less than 3 m above substrate) on limestone faces, or on nearby small trees, roots, or lianas. Two eggs are visible in paratypes (NMV75958 and NMV75959) at varying stages of development.

Above 1000 m.a.s.l. Cyrtodactylus tanim n. sp. was the only gecko present, but at the two lower elevation sites (less than 900 m.a.s.l.) it occurred sympatrically with C. capreoloides and C. serratus. No habitat segregation with the former was obvious. Cyrtodactylus serratus appeared to be much rarer (six specimens in three weeks) and was observed at greater heights in the forest strata (e.g. on lianas or in larger forest trees more than 3 m above the ground), suggesting this much larger species is more arboreal than Cyrtodactylus tanim n. sp.

Figure 8. Habitat of Cyrtodactylus tanim n. sp.: lower montane forest on karst basement in Western Province, Papua New Guinea. Photograph: Paul M. Oliver. 

 Etymology: ‘Tanim’, ‘Tanem’ or ‘Tanemkan’ is the ‘tokples’ name that Faiwol speakers from western Papua New Guinea gave specifically for Cyrtodactylus geckos, both on this survey, and earlier surveys undertaken by Fred Parker around Wangbin and Migalsimbip Villages in 1969 (personal communication). Incidentally, several local people including experienced hunters, showed distaste for Cyrtodactylus geckos, and were reluctant to touch, hold, or in the case of large specimens even look at them.

Stuart V. Nielsen and Paul M. Oliver. 2017. Morphological and Genetic Evidence for A New Karst Specialist Lizard from New Guinea (Cyrtodactylus: Gekkonidae).  Royal Society Open Science.  DOI: 10.1098/rsos.170781

 twitter.com/StuartVNielsen/status/931188894615457793

[Paleontology • 2017] Avicranium renestoi • A Bird-like Skull in A Triassic Diapsid Reptile Increases Heterogeneity of the Morphological and Phylogenetic Radiation of Diapsida

  Avicranium renestoi Pritchard & Nesbitt, 2017

  DOI:10.1098/rsos.170499 

Illustration: Matt Celeskey‏ @clepsydrops 

Abstract

The Triassic Period saw the first appearance of numerous amniote lineages (e.g. Lepidosauria, Archosauria, Mammalia) that defined Mesozoic ecosystems following the end Permian Mass Extinction, as well as the first major morphological diversification of crown-group reptiles. Unfortunately, much of our understanding of this event comes from the record of large-bodied reptiles (total body length > 1 m). Here we present a new species of drepanosaurid (small-bodied, chameleon-like diapsids) from the Upper Triassic Chinle Formation of New Mexico. Using reconstructions of micro-computed tomography data, we reveal the three-dimensional skull osteology of this clade for the first time. The skull presents many archaic anatomical traits unknown in Triassic crown-group reptiles (e.g. absence of bony support for the external ear), whereas other traits (e.g. toothless rostrum, anteriorly directed orbits, inflated endocranium) resemble derived avian theropods. A phylogenetic analysis of Permo-Triassic diapsids supports the hypothesis that drepanosaurs are an archaic lineage that originated in the Permian, far removed from crown-group Reptilia. The phylogenetic position of drepanosaurids indicates the presence of archaic Permian clades among Triassic small reptile assemblages and that morphological convergence produced a remarkably bird-like skull nearly 100 Myr before one is known to have emerged in Theropoda.

KEYWORDS: reptilia, phylogeny, convergence, Permo-Triassic extinction, evolutionary radiation, Triassic

Avicranium renestoi Pritchard & Nesbitt, 2017 

Illustration: Matt Celeskey‏ @clepsydrops 

Figure 2. Line drawing of the restored skull of Avicranium renestoi based on the three-dimensional surface renderings of skull elements in AMNH FARB 30834.

Figure 3. Reconstructed skull of Avicranium renestoi based on rearticulated three-dimensional surface rendering of the skull bones of AMNH FARB 30834.
Callouts include (a) reconstructed endocast in dorsal view, (b) skull roof in dorsal view, (c) postorbital complex (consisting of postfrontal and postorbital) in anterior view, (d) braincase and stapes in posterior view, (e) palatal complex in ventral view, (f) left quadrate in posterior view and (g) braincase and stapes in left lateral view. All bones have been rearticulated based on the facets of the reconstructed elements.

Abbreviations: fb, forebrain; mb, midbrain; pa, parietal; pf, postfrontal; pl, palatine; po, postorbital; pt, pterygoid; qu, quadrate; st, stapes; su, supratemporal. 

Systematic palaeontology

Diapsida

 Drepanosauromorpha 

 Drepanosauridae 

  Avicranium renestoi, n. gen., n. sp.

  Etymology: Avicranium, from aves (Latin for bird) and cranium (Latin for cranium), in reference to the suite of bird-like morphologies present in the holotype skull; renestoi, for Silvio Renesto, who described much of the drepanosauromorph fossil record from Triassic Italy.

  Holotype: AMNH FARB 30834, partial skull and articulated cervical series. Additional drepanosaurid caudal vertebrae and limb fragments are preserved in the block, but are not clearly associated with the individual to which the skull and cervical vertebrae belong.

  Locality: Coelophysis Quarry (‘siltstone member’, Chinle Formation). Recovered during preparation of the holotype block of the shuvosaurid pseudosuchian Effigia okeeffeae by S.J.N. [12].

 Diagnosis: Specimens for anatomical comparisons are listed in appendix C. A drepanosaurid diapsid differing from Hypuronector limnaios, Megalancosaurus preonensis and Vallesaurus cenensis (the only drepanosauromorphs with skull material) in the complete absence of teeth, a dorsoventrally taller retroarticular process with a triangular shape in lateral view, and cervical neural spines with subequal anteroposterior lengths and transverse widths.

Adam C. Pritchard and Sterling J. Nesbitt. 2017. A Bird-like Skull in A Triassic Diapsid Reptile Increases Heterogeneity of the Morphological and Phylogenetic Radiation of Diapsida. ROYAL SOCIETY OPEN SCIENCE.   DOI: 10.1098/rsos.170499 

 twitter.com/PastTimePaleo/status/918164972307349504 et @VTechmeetsPaleo

 twitter.com/clepsydrops/status/918235766165184512