Sunday, August 20, 2017

[Herpetology • 2017] Species Delimitation with Gene Flow: A Methodological Comparison and Population Genomics Approach to Elucidate Cryptic Species Boundaries in Malaysian Torrent Frogs


DOI: 10.1111/mec.14296 

Abstract

Accurately delimiting species boundaries is a non-trivial undertaking that can have significant effects on downstream inferences. We compared the efficacy of commonly-used species delimitation methods (SDMs) and a population genomics approach based on genome-wide single nucleotide polymorphisms (SNPs) to assess lineage separation in the Malaysian Torrent Frog Complex currently recognized as a single species (Amolops larutensis). First, we used morphological, mitochondrial DNA and genome-wide SNPs to identify putative species boundaries by implementing non-coalescent and coalescent-based SDMs (mPTP, iBPP, BFD*). We then tested the validity of putative boundaries by estimating spatiotemporal gene flow (fastsimcoal2, ABBA-BABA) to assess the extent of genetic isolation among putative species. Our results show that the A. larutensis complex runs the gamut of the speciation continuum from highly divergent, genetically isolated lineages (mean Fst = 0.9) to differentiating populations involving recent gene flow (mean Fst = 0.05; Nm > 5). As expected, SDMs were effective at delimiting divergent lineages in the absence of gene flow but overestimated species in the presence of marked population structure and gene flow. However, using a population genomics approach and the concept of species as separately evolving metapopulation lineages as the only necessary property of a species, we were able to objectively elucidate cryptic species boundaries in the presence of past and present gene flow. This study does not discount the utility of SDMs but highlights the danger of violating model assumptions and the importance of carefully considering methods that appropriately fit the diversification history of a particular system.

Keywords: Amolops, migration rate, fastsimcoal2, site frequency spectrum, gene flow, single-nucleotide polymorphism 




Kin Onn Chan, Alana M. Alexander, Lee L. Grismer, Yong-Chao Su, Jesse L. Grismer, Evan S. H. Quah and Rafe M. Brown. 2017. Species Delimitation with Gene Flow: A Methodological Comparison and Population Genomics Approach to Elucidate Cryptic Species Boundaries in Malaysian Torrent Frogs.  Molecular Ecology. DOI: 10.1111/mec.14296 

[Ichthyology • 2017] Five New Species of Marine Gobies of the Genus Grallenia (Teleostei: Gobiidae) from the tropical western Pacific Ocean


Grallenia rubrilineata  Allen & Erdmann, 2017

Abstract

Five new species belonging to the gobiid fish genus Grallenia of the tropical western Pacific Ocean are described from sand-bottom habitats. Grallenia compta n. sp. (11 specimens, 14.9–17.3 mm SL) from Milne Bay Province, Papua New Guinea and Grallenia rubrilineata n. sp. (81 specimens, 8.8–15.8 mm SL) from Luzon, Philippines share a suite of features that comprises an absence of cephalic sensory-canal pores, a rectangular first dorsal fin without a filamentous extension of the first spine, and the anterior and posterior scales separated by a scaleless gap, with 15–22 longitudinal scales in the posterior series. The two species differ from each other in dorsal- and anal fin-ray counts (8–9 for G. compta n. sp. vs. 9–11, usually 10, for G. rubrilineata n. sp.), scalation patterns, and coloration. A third new species, Grallenia dimorpha n. sp. (34 specimens, 9.8–16.7 mm SL) from Papua New Guinea is similar, except it has a continuous series of longitudinal scales without a gap, and females possess a triangular first dorsal fin featuring a filamentous extension of the first spine. The last two species, Grallenia lauensis n. sp. (two females, 11.1–11.4 mm SL) and Grallenia solomonensis n. sp. (three females, 11.4–12.5 mm SL), are described from Fiji and the Solomon Islands, respectively. They exhibit similar diagnostic features including the presence of cephalic sensory-canal pores, usually 7 segmented dorsal- and anal-fin rays, and most body scales restricted to the caudal peduncle. Grallenia solomonensis n. sp. differs from G. lauensis n. sp. in having several mid-lateral scales immediately behind the pectoral-fin base (vs. none), 16 (vs. 15) pectoral-fin rays, pelvic-fin rays with 2–3 branch points (vs. a single point), and a truncate (vs. slightly emarginate) caudal fin. An additional 33 non-type specimens, 7.0–15.6 mm SL, from Australia (southern Great Barrier Reef and northwestern Coral Sea) are provisionally identified as G. lauensis n. sp. However, at least some Australian specimens differ slightly in possessing branched segmented dorsal-fin rays and pelvic-fin rays with more than one branch point. Although fins are damaged in most specimens, two Australian males exhibit a long, filamentous first dorsal-fin spine.

Key words: taxonomy, systematics, ichthyology, coral-reef fishes, Indo-Pacific Ocean, Papua New Guinea, Philippines, Solomon Islands, Fiji, Australia, sand habitat




Grallenia compta, n. sp.
 Ornamented Goby

Etymology. The species is named compta (Latin: ornamented), with reference to the orange markings on the head, body, and fins. It is treated as a feminine singular adjective.

Distribution and habitat. The new species is currently known only from Sideia Island in Milne Bay Province of Papua New Guinea (Fig. 6), but is no doubt more widespread in this large marine province. The habitat consists of large (5–10 m2 ), flat, sandy areas surrounded by live coral, in depths of about 14–15 m.



Figure 5: Adult males of species of Grallenia: A) G. compta; B) G. dimorpha; C) G. rubrilineata (G.R. Allen & M.V. Erdmann).



Figure 10. Grallenia dimorpha, male (upper) and female (lower), approx. 15 mm SL, underwater photographs in 16 m, White Island, West New Britain Province, Papua New Guinea (G.R. Allen). 

Grallenia dimorpha, n. sp.
 Dimorphic Goby

Etymology. The species is named dimorpha (Latin: two shapes) with reference to the sexual dimorphism in relation to dorsal-fin shape. It is treated as a feminine singular adjective. 

Distribution and habitat. The new species is currently known only from Papua New Guinea (Fig. 6). The type series was collected off the southern coast of New Britain Island and the non-type specimens from the vicinity of Madang and near Port Moresby. The habitat consists of sandy substrate in about 8–18 m.

Figure 14. Grallenia lauensis, female, approx. 11 mm SL, underwater photographs in 30–35 m, Lau Archipelago, Fiji (M.V. Erdmann). 

Grallenia lauensis, n. sp. 
Lau Goby

Etymology. The species is named lauensis with reference to the Lau Archipelago type locality. 

Distribution and habitat. The new species is currently known from the southern Lau Archipelago of southeastern Fiji and 33 non-type specimens from the Great Barrier Reef and northwestern Coral Sea. The Lau habitat consists of extensive gradual slopes of clean white sand in 30–35m depth. Both Lau sites were located in channel passes from the outer reef to extensive inner lagoons, and were hence subject to frequent strong currents and high rates of water exchange.


Figure 18. Grallenia rubrilineata, male (right), female (center), and juvenile (left) approx. 8–15 mm SL, underwater photograph in 15 m, Ligpo Island near Anilao, Batangas Province, Philippines (G.R. Allen).

Grallenia rubrilineata, n. sp. 
Redstripe Goby

Etymology. The species is named rubrilineata (Latin: “red-lined” or “red-striped”), with reference to the characteristic marking on the dorsal fin of adult males. It is treated as a feminine compound adjective.

 Distribution and habitat. The new species is currently known from the Philippines, including the type locality near Anilao in Batangas Province, Luzon, and on the basis of a photograph from Dauin, Negros in the Central Visayas Group. A female specimen examined at WAM (P.30410-015), 18 mm SL, from Bohaydulong Island, Sabah State, Malaysia is probably G. rubrilineata, judging from fin-ray counts, scale pattern, and lack of head pores; however, additional specimens, including males, would be required to verify this identification. The habitat at Anilao consists of extensive areas of sand/silt substrate in about 12–15 m. The new species was very abundant in some areas, including the type locality, with an estimated abundance of 10–15 individuals per square meter. It was typically seen in small groups.



Grallenia solomonensis, n. sp. 
Solomons Goby

Etymology. The species is named solomonensis with reference to the Solomon Islands type locality.


Gerald R. Allen and Mark V. Erdmann. 2017. Description of Five New Species of Marine Gobies (Teleostei: Gobiidae) of the Genus Grallenia from the tropical western Pacific Ocean. Journal of the Ocean Science Foundation. 27; 20–47.  http://www.oceansciencefoundation.org/josf27c.html

[PaleoMammalogy • 2017] Xibalbaonyx oviceps • A New Megalonychid Ground Sloth (Folivora, Xenarthra) from the Late Pleistocene of the Yucatán Peninsula, Mexico, and Its Paleobiogeographic Significance


Xibalbaonyx oviceps 
Stinnesbeck, Frey, Olguín, Stinnesbeck, Zell, Mallison, González, Núñez, Morlet, Mata, Sanvicente, Hering & Sandoval, 2017.

 DOI: 10.1007/s12542-017-0349-5 

Abstract
Here we describe a new genus and species of giant ground sloth, Xibalbaonyx oviceps (Megalonychidae, Xenarthra), from the drowned cave system of the northeastern Yucatán Peninsula. The specimen is Late Pleistocene in age and was discovered in the Zapote sinkhole (cenote) near Puerto Morelos in the Mexican state of Quintana Roo. Xibalbaonyx oviceps differs significantly from all hitherto known Megalonychidae including those from the Greater Antilles and South America. The new taxon suggests a local Caribbean radiation of ground sloths during the Late Pleistocene, which is consistent with the dispersal of the group along a Mexican corridor.

Keywords: Ground sloths, Pleistocene, Yucatán Peninsula, Mexico 


Systematic palaeontology
Superorder Xenarthra Cope, 1889
Order Pilosa Flower, 1883

Superfamily Megatherioidea Gray, 1821
Family Megalonychidae Gervais, 1855

Diagnosis of the family. Xibalbaonyx oviceps is identified as a member of Megalonychidae based on the following features: dorsal contour of skull evenly convex in lateral view. The glenoid fossa is mediolaterally widened, its posterior surface smooth and the fossa is well separated from the porus acusticus. The lateral plate of the entotympanic is thin with a medial expansion and weak participation in the floor of the tympanic cavity. The paroccipital process is well developed (Patterson et al. 1992; Gaudin 1995, 2004; McDonald et al. 2013b).


Fig. 4: Xibalbaonyx oviceps (Za2014-01) skull in lateral view (left side). 

Fig. 3: Xibalbaonyx oviceps in situ within the Zapote cenote; Skull and mandible (Za2014-01, -05)

Xibalbaonyx oviceps gen. et sp. nov.

Etymology. For the genus: Xibalbá = Maya for “underground” or “place of fear,” dedicated to the cave divers who dive into the “underworld,” the cenotes, and collect the fossils under risky conditions, but also in honor of the Yucatán Peninsula, which is also called the Maya region; “őνυξ” (onyx) = Greek for “claw” or “finger nail;” for the species: oviceps from ovum = Latin for “egg” and caput = “head,” “egghead,” referring to the regularly domed skull roof of the specimen.

Stratigraphic and geographic distribution. The Cenote Zapote 16 Q 0486971 UTM 2305968, Ruta de los Cenotes Puerto Morelos Quintana Roo, Mexico. Late Pleistocene and/or Early Holocene (9.305 ± 35 14C bp, 10.647–10.305 cal bp).

.....


 Conclusions: 
The well-preserved skull and mandible of a ground sloth discovered in the Zapote cenote Cave near Puerto Morelos on the northeastern Yucatán Peninsula of Mexico is here described as a new genus and species of Megalonychidae. The individual, here named Xibalbaonyx oviceps, has a dental formula of 5/4 including a greatly enlarged caniniform tooth of triangular cross-section. This caniniform is separated by a long diastema from the molariform tooth rows in both the lower and upper jaw. The molariform teeth show oval, rounded rectangular to reniform (McDonald et al. 2013b) occlusal shapes with transverse crests. All teeth except for the upper caniniforms, show striations and apicobasal sulci that may be expressed as shallow grooves or deep sulci. The ascending process of the jugal is longer than the descending and middle process of the jugal. The pterygoids are inflated. The glenoid fossa is transversally widened. The skull is elongated and narrow, with a nasional impression on the nasals. The temporal lines are widely separated and do not form a sagittal crest. The skull is narrow and gracile compared that of other Megalonychidae of similar size, such as Megalonyx or Ahytherium. The Zapote ground sloth was a subadult individual, based on the degree of suture fusion in the skull, faint temporal lines and the condition of the occlusion faces of the molariforms. To present knowledge Xibalbaonyx appears to have been endemic on the Yucatán Peninsula, suggesting a local microevolution on this karst desert during the Late Pleistocene.


Sarah R. Stinnesbeck, Eberhard Frey, Jerónimo Avíles Olguín, Wolfgang Stinnesbeck, Patrick Zell, Heinrich Mallison, Arturo González González, Eugenio Aceves Núñez, Adriana Velázquez Morlet, Alejandro Terrazas Mata, Martha Benavente Sanvicente, Fabio Hering and Carmen Rojas Sandoval. 2017. Xibalbaonyx oviceps, A New Megalonychid Ground Sloth (Folivora, Xenarthra) from the Late Pleistocene of the Yucatán Peninsula, Mexico, and Its Paleobiogeographic Significance. PalZ [Paläontologische Zeitschrift]. 91(2); 245–271.   DOI: 10.1007/s12542-017-0349-5

Ancient species of giant sloth discovered in Mexico  ctv.news/M8rqjqN

Kurzfassung: Die Unterwasserhöhlen auf der nordöstlichen Halbinsel Yukatan zeigen eine artenreiche Ansammlung von Großsäugern aus dem späten Pleistozän und frühen Holozän. Hier beschreiben wir die neue Gattung und Art eines Riesenfaultiers, Xibalbaonyx oviceps (Megalonychidae, Xenarthra), aus der Zapote Doline (Cenote) in der Nähe von Puerto Morelos im mexikanischen Bundesstaat Quintana Roo. Das Exemplar unterscheidet sich signifikant von allen bisher dokumentierten Megalonychidae einschließlich derjenigen von den Großen Antillen und aus Südamerika. Das neue Taxon deutet auf eine lokale karibische Radiation von Bodenfaultieren währen des Spätpleistozäns hin, die mit der Ausbreitung der Gruppe entlang des mexikanischen Korridors übereinstimmt.

Schlüsselwörter: Bodenfaultiere Pleistozän Yukatan Halbinsel Mexiko 

[Ichthyology • 2017] Taxonomic Revision of the Seasonal Killifish Genus Nothobranchius (Cyprinodontoidei: Aplocheilidae) from Zanzibar, East Africa



ABSTRACT
Nothobranchius guentheri and Nothobranchius melanospilus, the two seasonal killifishes of the genus Nothobranchius occurring in Zanzibar Island, Tanzania, were involved in past taxonomical mistakes and are still misidentified in museum collections. A historical review is herein presented and both species are redescribed on the basis of type material and recent collections. Nothobranchius guentheri, a popular aquarium fish, is endemic to Zanzibar, and N. melanospilus, geographically widespread in East Africa, occurring both in Zanzibar and in continental river basins. These species are distinguished by a series of morphological features not previously reported in the literature, including pre-dorsal length and relative position of the anterior portion of the dorsal-fin skeletal support and vertebrae; number of gill-rakers of the first branchial arch, caudal-fin rays, scales of the longitudinal series, series of scales around caudal peduncle, and vertebrae; frontal squamation; and arrangement and number of neuromasts of the supraorbital series. The present taxonomic revision comprising N. guentheri and N. melanospilus, the oldest species names of the genus in the East African biodiversity hotspot, is important to improve the knowledge of the genus in a region where its taxonomy is still problematic

KEYWORDS: Biodiversity hotspot, East African coastal forests, systematics, Unguja Island


Figure 2. Nothobranchius guentheri (Pfeffer 1893), live exemplars: (a) UFRJ 8420, male, 33.1 mm SL; (b) UFRJ 8420, female, 29.3 mm SL.
Figure 6. Nothobranchius melanospilus (Pfeffer 1896), live exemplars: (a) UFRJ 6515, male, 32.6 mm SL; (b) UFRJ 6515, female, 31.1 mm SL.



Wilson J. E. M. Costa. 2017. Taxonomic Revision of the Seasonal Killifish Genus Nothobranchius from Zanzibar, East Africa (Cyprinodontoidei: Aplocheilidae). Journal of Natural History. 51(27-28); 1069-1624.  DOI: 10.1080/00222933.2017.1330976

Saturday, August 19, 2017

[Ichthyology • 2017] Schistura thavonei • A New Species of Loach (Teleostei: Nemacheilidae) from northwestern Laos


 Schistura thavonei  Kottelat, 2017

RAFFLES BULLETIN OF ZOOLOGY. 65


  Abstract
 Schistura thavonei, new species, is described from the Nam Ma, Mekong drainage, in Louang Namtha Province, northwestern Laos. It is distinguished from all other Nemacheilidae by its unique colour pattern made of two broad dark brown stripes (one middorsal, one midlateral) and between them a pale yellowish-brown stripe (iridescent in life); a row of 12–24 short black bars are located increasingly lower on the flank from head to tail, posterior-most ones restricted to the lower half of the body or forming blotches along the ventral midline of the caudal peduncle. Besides, it has an elongate body with a hump immediately behind the head, 8+7 branched caudalfin rays; and 9–10 total pectoral-fin rays. It was found in riffles, over gravel to stone bottom. 

Key words. Cobitoidei, Schistura, Laos, Mekong basin, stone loach



Diagnosis. Schistura thavonei is distinguished from the other species of the genus by its unique colour pattern made of two broad dark brown stripes (one middorsal, one midlateral) and between them a pale yellowish-brown stripe (iridescent copper to orange in life) from the upper extremity of the gill opening to the upper half of the base of the caudal fin; overimposed to the midlateral stripe, a row of 12–24 short black bars, located increasingly lower on the flank from head to tail, posterior-most ones restricted to the lower half of the body or forming blotches along the ventral midline of the caudal peduncle. Additional characters useful for identification but not unique to the species are: body very elongate (depth 6.2–7.2 times in SL), with a marked hump behind the head; male without suborbital flap; 8+7 branched caudal-fin rays; 7½ branched dorsal fin rays; 9–10 pectoral-fin rays.



Notes on biology. A dissected female (CMK 25066, 46.6 mm SL) had unripe ovaries with white, irregular, not mature, ova about 1.0 mm diameter. The stomach of a 42.4 mm SL specimen was filled with insect larvae about 2–5 mm long. Schistura thavonei was observed in clear water [as expected for a benthic fish with bright coloration and contrasted pattern]. At all sites, S. thavonei has been collected in stretches of streams with riffles (in the sheltered parts with somewhat quieter current), over gravel to stone bottom (Fig. 7).

Distribution. Schistura thavonei is presently known only from the watershed of the Nam Ma in Louang Namtha Province, a tributary of the Mekong, in northeastern Laos (not to be confused with the Nam Ma in Houa Phan Province, which flows to Vietnam and enters the Gulf of Tonkin).

Etymology. The species is named for Mr. Thavone Phommavong, in appreciation for his help and companionship during several, and sometimes difficult, fish surveys in Laos. A noun in genitive.



Maurice Kottelat. 2017. Schistura thavonei, A New Species of Loach from northwestern Laos (Teleostei: Nemacheilidae). RAFFLES BULLETIN OF ZOOLOGY. 65: 395–403

[Entomology • 2017] Species Checklist of Orthoptera (Insecta) from Sakaerat Environmental Research Station, Thailand


  Some Orthoptera Species from Sakaerat Environmental Research Station, Thailand 

Dawwrueng, Tan, Artchawakom & Waengsothorn, 2017. 
  DOI:  10.11646/zootaxa.4306.3.1

Abstract

Sakaerat Biosphere Reserve is one of the four Biosphere Reserves in Thailand. It is situated at Khorat Plateau and comprises of mainly dry evergreen forest and dry dipterocarp forest. Despite studies that document its rich biodiversity, there was no concerted study on the orthopteran diversity. Recent sampling by the authors in Sakaerat led to the discovery of numerous undescribed species. A checklist, first for the place, is also reported here, each species represented with a habitus photograph. In total, 128 species of Orthoptera from 11 families were recorded. Caelifera (grasshoppers) were represented with five families and Ensifera (crickets and katydids) were represented with six families, making up 10 of the 16 lineages in the orthoptera phylogeny.

Keywords: Orthoptera, Caelifera, Ensifera, diversity, taxonomy, Nakhon Ratchasima, UNESCO Biosphere Reserve

Pattarawich Dawwrueng, Ming Kai Tan, Taksin Artchawakom and Surachit Waengsothorn. 2017.  Species Checklist of Orthoptera (Insecta) from Sakaerat Environmental Research Station, Thailand (Southeast Asia). Zootaxa. 4306(3); 301–324. DOI:  10.11646/zootaxa.4306.3.1

[Paleontology • 2017] A Dinosaur Missing-Link? Chilesaurus and the Early Evolution of Ornithischian Dinosaurs


Chilesaurus diegosuarezi 
Novas, Salgado, Suárez, Agnolín, Ezcurra, Chimento, de la Cruz, Isasi, Vargas & Rubilar-Rogers, 2015

DOI: 10.1098/rsbl.2017.0220  & DOI: 10.1038/nature14307
Illustration: Gabriel Lío

Abstract

The enigmatic dinosaur taxon Chilesaurus diegosuarezi was originally described as a tetanuran theropod, but this species possesses a highly unusual combination of features that could provide evidence of alternative phylogenetic positions within the clade. In order to test the relationships of Chilesaurus, we added it to a new dataset of early dinosaurs and other dinosauromorphs. Our analyses recover Chilesaurus in a novel position, as the earliest diverging member of Ornithischia, rather than a tetanuran theropod. The basal position of Chilesaurus within the clade and its suite of anatomical characters suggest that it might represent a ‘transitional’ taxon, bridging the morphological gap between Theropoda and Ornithischia, thereby offering potential insights into the earliest stages of ornithischian evolution, which were previously obscure. For example, our results suggest that pubic retroversion occurred prior to some of the craniodental and postcranial modifications that previously diagnosed the clade (e.g. the presence of a predentary bone and ossified tendons).

KEYWORDSArchosauria, Dinosauria, Ornithischia, systematics: phylogeny, Jurassic


Figure 2. Ornithischian features of Chilesaurus. (a) Simplified tree with key acquisitions marked on;
(b) right dentary of Chilesaurus (SNGM-1935) in lateral view; (c) right dentary of Heterodontosaurus (SAM-PK-K1332) in lateral view; (d) pelvic girdle of Chilesaurus SNGM-1936 in lateral view; (e) pelvic girdle of Agilisaurus (ZDM T6011) in lateral view; (f) right femur of Chilesaurus (SNGM-1935) in anterior view; (g) right tibia and fibula of Chilesaurus (SNGM-1935) in posterior view.
Numbers indicate the acquisition of key ornithischian synapomorphies within the clade: 1, complete loss of recurvature in maxillary and dentary teeth; 2, edentulous anterior end of the dentary; 3, predentary bone at the anterior end of the lower jaw; 4, retroversion of the pubis; 5, rod-like pubic shaft; 6, pubic symphysis restricted to the distal end; 7, anteriorly elongate preacetabular process; 8, broadened, wing-like anterior trochanter; 9, fibula less than half the width of the tibia at midshaft. Dark grey circles denote unknown in Pisanosaurus.



Conclusion: 
This study identifies Chilesaurus as a transitional ornithischian taxon and suggests that the unique suite of anatomical features it possesses could be informative not only in unravelling dinosaur interrelationships, but also in shedding light on the evolution of the anatomical peculiarities that characterize ornithischians. Paradoxically, this early diverging lineage is of Late Jurassic age, implying an extensive ghost lineage between it and other ornithischians and basal theropods. If this hypothesis is correct, this ghost lineage suggests that other similar animals await discovery in Late Triassic–Middle Jurassic deposits. This study highlights the importance of broad taxon sampling when attempting to assess the phylogenetic affinities of enigmatic taxa such as Chilesaurus and also demonstrates the utility of this new early dinosaur dataset for testing the relationships proposed for other problematic dinosauromorph taxa.




Matthew G. Baron and Paul M. Barrett. 2017. A Dinosaur Missing-Link? Chilesaurus and the Early Evolution of Ornithischian Dinosaurs. Biology Letters. 13(8); 20170220. DOI: 10.1098/rsbl.2017.0220.


Abstract: Many dinosaur skeletons show evidence of behavior, including feeding, predation, nesting, and parental care. The resting posture of the forelimbs has been studied in some theropod species, in relation to the acquisition of flight in advanced maniraptoran theropods. Chilesaurus diegosuarezi is a bizarre tetanuran recently described from the Toqui Formation (latest Tithonian) of southern Chile that is represented by multiple well-preserved and articulated specimens. The aim of the present work is to analyze the forelimb posture of four articulated specimens of Chilesaurus: SNGM-1935 (holotype), SNGM-1936, SNGM-1937, SNGM-1938; focusing on its anatomical description, and phylogenetic and behavioral implications. All the preserved specimens of Chilesaurus show strongly ventrally flexed arms with the hands oriented backwards, an arrangement that closely resembles those in dinosaur specimens previously described as preserving resting posture, such as Mei long, Sinornithoides youngi, and Albinykus baatar. As a result, it seems that individuals of Chilesaurus have been in passive activity (e.g. feeding, resting) when they were buried quickly, allowing their fossilization in life position and preserving the forelimb resting posture. The arrangement of the forelimb bones in Chilesaurus could show the first evidences of the structures linked to the muscles that flex the forearms, features related with the acquisition of flying control in advanced maniraptorans.


Nicolás R. Chimento, Federico L. Agnolin, Fernando E. Novas, Martín D. Ezcurra, Leonardo Salgado, Marcelo P. Isasi, Manuel Suárez, Rita De La Cruz, David Rubilar-Rogers and Alexander O. Vargas. 2017. Forelimb posture in Chilesaurus diegosuarezi (Dinosauria, Theropoda) and its behavioral and phylogenetic implications. Ameghiniana. in press. DOI: 10.5710/AMGH.11.06.2017.3088.

Study identifies dinosaur ‘missing link’

Fernando E. Novas, Leonardo Salgado, Manuel Suárez, Federico L. Agnolín, Martín D. Ezcurra, Nicolás R. Chimento, Rita de la Cruz, Marcelo P. Isasi, Alexander O. Vargas and David Rubilar-Rogers. 2015. An Enigmatic Plant-eating Theropod from the Late Jurassic period of Chile. Nature. (2015) DOI: 10.1038/nature14307

[PaleoMammalogy • 2017] Anatoliadelphys maasae • Skeleton of An Unusual, Cat-sized Marsupial Relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian) of Turkey


Anatoliadelphys maasae  Maga & Beck, 2017


Abstract

We describe a near-complete, three-dimensionally preserved skeleton of a metatherian (relative of modern marsupials) from the middle Eocene (Lutetian: 44–43 million years ago) Lülük member of the Uzunçarşıdere Formation, central Turkey. With an estimated body mass of 3–4 kg, about the size of a domestic cat (Felis catus) or spotted quoll (Dasyurus maculatus), it is an order of magnitude larger than the largest fossil metatherians previously known from the Cenozoic of the northern hemisphere. This new taxon is characterised by large, broad third premolars that probably represent adaptations for hard object feeding (durophagy), and its craniodental morphology suggests the capacity to generate high bite forces. Qualitative and quantitative functional analyses of its postcranial skeleton indicate that it was probably scansorial and relatively agile, perhaps broadly similar in locomotor mode to the spotted quoll, but with a greater capacity for climbing and grasping. Bayesian phylogenetic analysis of a total evidence dataset comprising 259 morphological characters and 9kb of DNA sequence data from five nuclear protein-coding genes, using both undated and “tip-and-node dating” approaches, place the new taxon outside the marsupial crown-clade, but within the clade Marsupialiformes. It demonstrates that at least one metatherian lineage evolved to occupy the small-medium, meso- or hypo-carnivore niche in the northern hemisphere during the early Cenozoic, at a time when there were numerous eutherians (placentals and their fossil relatives) filling similar niches. However, the known mammal fauna from Uzunçarşıdere Formation appears highly endemic, and geological evidence suggests that this region of Turkey was an island for at least part of the early Cenozoic, and so the new taxon may have evolved in isolation from potential eutherian competitors. Nevertheless, the new taxon reveals previously unsuspected ecomorphological disparity among northern hemisphere metatherians during the first half of the Cenozoic.


Systematic palaeontology

Mammalia; Theria
Metatheria; Marsupialiformes

Anatoliadelphys gen. nov.  
Anatoliadelphys maasae sp. nov.  

Etymology: Anatolia (Greek): the geographic name for the Asian part of Turkey; delphys (Greek): uterus, a common suffix for marsupials and their fossil relatives; maasae: in honour of Dr. Mary Maas and her contributions to Paleogene mammalian palaeontology, particularly in Turkey.

Holotype: Ankara Üniversitesi Jeoloji Müzesi (AÜJM) specimen 2002–25, which comprises a fragmented partial cranium, both dentaries, and associated postcranial elements, including most of the vertebral column, partial pectoral and pelvic girdles, all of the long limb bones, both calcanei, two metapodials, and a few phalanges.

Locality and age: AÜJM 2002–25 was collected from the Lülük member of the Uzunçarşıdere Formation (UCF), which is part of the small Orhaniye-Güvenç sedimentary basin located at the northwestern edge of the city of Ankara, approximately 5 km southwest of the town of Kazan, in central Turkey. The Lülük member is the lowest of the three members currently recognised within the UCF (together with the Gökdere [middle], and Sarıbeyler [upper] members), and is the source of all fossil mammals known from the UCF to date. AÜJM 2002–25 is from locality AK33, which is approximately 90m above the base of the UCF, at Memlik village. Until recently, the age of the UCF was poorly constrained, but a combination of U-Pb dating of zircons and magnetostratigraphy now support a date of 44–42 MYA (= Lutetian) for the formation as a whole, and 44–43 MYA for the Lülük member.

Diagnosis: Anatoliadelphys maasae differs from all other metatherians in the following combination of features: comparatively large size (estimated body mass 3–4 kg); premolars increase markedly in size posteriorly (occlusal area of p1 less than one sixth that of p3); P3 and p3 very large (similar in occlusal area to M2 and m2 respectively) and also broad (labiolingual width:mesiodistal length ratio is 0.89 for P3 and 0.7 for p3); modified tribosphenic molar dentition, in which M1-3 and m1-4 increase markedly in size posteriorly (occlusal area of M1 approximately one third that of M3; occlusal area of m1 approximately one seventh that of m4); upper molars with cingula extending along the anterior and posterior margins; protocone large but conules indistinct or absent; metacone taller than the paracone on M3 but smaller than the paracone on M4; centrocrista v-shaped on M3, with the premetacrista extending labially to stylar cusp D; centrocrista straight on M4; parastylar lobe very large on M4; anterior cingulid weakly developed on m3-4; m4 trigonid dominated by enormous protoconid, with paraconid and metaconid both greatly reduced; preentocristid and cristid obliqua of m3-4 both with carnassial notch; posterior cingulid present but very faint on m3-4; strongly curved radius and tibia; femur with prominent third trochanter, well-marked trochlea and distal condyles of approximately equal width; calcaneus with medially-inflected tuber, large peroneal process with prominent groove for peroneus longus tendon, concave calcaneocuboid facet, and prominent pit (probably for plantar calcaneocuboid ligament) on ventral surface.

.....

Fig 1. Holotype skeleton of Anatoliadelphys maasae (AÜJM 2002–25). Scale bar = 5 cm. 

Reconstruction of the Anatoliadelphys maasae.
Illustration: Peter Schouten 


A. Murat Maga and Robin M. D. Beck. 2017. Skeleton of An Unusual, Cat-sized Marsupial Relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian: 44-43 million years ago) of Turkey.  PLoS ONE. 12(8); e0181712.  DOI: 10.1371/journal.pone.0181712


Cenozoic carnivore from Turkey may have evolved without placental competitors  phy.so/422094230 via @physorg_com
Ancient Carnivorous Dread-Possum Is Upending The History Of Mammals | Gizmodo Australia (via @GizmodoAU)  www.gizmodo.com.au/2017/08/ancient-carnivorous-dread-possum-is-upending-the-history-of-mammals/

[Botany • 2017] Argostemma cordatum • A New Species (Rubiaceae) from southern Vietnam


Argostemma cordatum Nuraliev


Abstract

Argostemma cordatum, a new species of Rubiaceae, is described and illustrated. The species was discovered in 2014 during a botanical survey of the Chu Yang Sin National Park (Dak Lak province, Southern Vietnam). Argostemma cordatum possesses a solitary large leaf per plant (along with one very small leaf). The new species differs from morphologically similar species mainly by the small size of the enlarged leaf and cordate base of the enlarged leaf. It is also characterized by the following features: plant completely glabrous, stipules minute and reduced to papillate warts, inflorescence with all axes elongated, anthers coherent into anther cone and dehiscent by longitudinal slits, style slightly exserted. An extended description of the vegetation in the area inhabited by A. cordatum is provided.

Keywords: Argostemma, taxonomy, Southern Vietnam, Chu Yang Sin National Park, flora, biodiversity, Eudicots

  
FIGURE 2. Argostemma cordatum at type locality.
A. General view of population. B. Flowering individual. D. Dichasium with flower buds. E. Flower, apical and oblique view.
Nuraliev, Kuznetsov, Kuznetsova 960. All photos by M. Nuraliev.  

Argostemma cordatum Nuraliev, sp. nov.

Etymology:— The specific epithet “cordatum” refers to the prominently cordate base of large leaf which distinguishes the new species from its relatives.  


Maxim S. Nuraliev, Anton S. Beer, Andrey N. Kuznetsov and Svetlana P. Kuznetsova. 2017. 
Argostemma cordatum (Rubiaceae), A New Species from Vietnam.
 Phytotaxa. 317(1); 42–52. DOI:  10.11646/phytotaxa.317.1.4

[Gastropoda • 2017] Attenborougharion gen. nov. (Mollusca: Pulmonata: Helicarionidae): A Likely Case of Convergent Evolution in southeastern Tasmania


Attenborougharion rubicundus (Dartnall & Kershaw, 1978)

Hyman & Köhler, 2017  

Abstract
Helicarion Férussac, 1821 from southeastern Australia currently comprises five species of endemic semislugs. Analyses of comparative morphological data and partial sequences of the mitochondrial genes cytochrome c oxidase subunit I (COI) and 16S rRNA (16S) reveal that one of these species, Helicarion rubicundus Dartnall & Kershaw, 1978, which is restricted to southeastern Tasmania, is not closely related to the other known species of this genus. This species is distinguished from Helicarion in several key morphological characters, such as the bright two-toned red and green colouration of its larger body with a flattened tail that is keeled only at the tip, the triangular shape of the pneumostome, the degree and type of folding present in the spermoviduct and free oviduct, the presence of a longer, more slender bursa copulatrix, the presence of a small epiphallic caecum and a hooked flagellum, and the presence of irregular longitudinal pilasters in the penial interior in contrast to the v-shaped rows of papillose lamellae seen in Helicarion. Moreover, the mitochondrial phylogeny provides evidence that this species is phylogenetically distinct from Helicarion as well as any other currently described genus from southeastern Australia. Based on these findings, we here describe a new genusAttenborougharion, for this species.

Keywords: Helicarionoidea; morphology; mitochondrial DNA; land snail; taxonomy.



Figure 1. Living animal of Attenborougharion rubicundus from Forestier Peninsula (QVM 9:15514).
photo: Simon Grove, TMAG. 

Systematics 

Attenborougharion gen. nov.
 Type species. Helicarion rubicundus Dartnall & Kershaw, 1978.

Etymology. Named for Sir David Attenborough, Lifetime Patron of the Australian Museum, in recognition of his lifetime’s contribution to the fields of natural science and conservation. The Latin noun arion refers to a “kind of snail or slug”; masculine.

A new genus of snail has been named Attenborougharion in honour of Sir David Attenborough.
Photographer: James Morgan /  AustralianMuseum.net.au 

Diagnosis External appearance. Large, shell ear-shaped, flattened, thin, golden, glossy, whorls rounded, base membraneous. Protoconch with radial wrinkles near suture; otherwise sculptured with very faint beading and indistinct to absent spiral grooves; teleoconch with very fine, indistinct spiral grooves and more prominent radial growth lines. Body colour green and burgundy. Mantle lobes and shell lappets of moderate size, none fused; shell lappets elongate, lacking pigmented warts; slime network prominent; caudal horn well-developed. Keel confined to very tip of tail; most of tail dorsally

Attenborougharion rubicundus (Dartnall & Kershaw, 1978) comb. nov. 
Helicarion rubicundus Dartnall & Kershaw, 1978: 2; Kershaw, 1980: 213.

Distribution and conservation status: Attenborougharion rubicundus is found only on the Tasman and Forestier Peninsulas in Tasmania (Taylor, 1991; Otley et al., 1999). The total known extent of occurrence of this species is 85 sq.km., leading to its listing as Vulnerable on the IUCN Red List of Threatened Species. In addition to its restricted range, within this area Attenborougharion rubicundus inhabits only closed wet forests and is not found in dry forests or damp sclerophyll forests (Otley eal., 1999), making it vulnerable to habitat loss through the effects of climate change as well as habitat destruction through changed land use.




  Isabel T. Hyman and Frank Köhler. 2017. Attenborougharion gen. nov. (Mollusca: Pulmonata: Helicarionidae): A Likely Case of Convergent Evolution in southeastern Tasmania. Records of the Australian Museum. 69(2): 65–72.  DOI: 10.3853/j.2201-4349.69.2017.1676

Friday, August 18, 2017

[Paleontology • 2017] Thaumatodracon wiedenrothi • A Morphometrically and Stratigraphically Intermediate New Rhomaleosaurid Plesiosaurian from the Lower Jurassic (Sinemurian) of Lyme Regis, England


Thaumatodracon wiedenrothi  Smith & Araújo, 2017

Illustration: L. Soares. DOI: 10.1127/pala/308/2017/89  

Abstract

An excellently preserved partial skeleton of a rhomaleosaurid plesiosaurian (NLMH 106. 058) from the Sinemurian (Lower Jurassic) of Lyme Regis, England, is described. The material consists of a complete cranium, mandible, and articulated cervical vertebral column. It is noteworthy because large-headed rhomaleosaurids are rare from this stratigraphic horizon and it is taxonomically distinct. The material is referred to a new taxonThaumatodracon wiedenrothi gen. nov. et sp. nov, diagnosed by two autapomorphies: 1. a pronounced transverse trough on the posterior margin of the dorsal ramus of the squamosal; 2. possibly paired anteriorly tapering triangular basioccipital processes. It also possesses a unique combination of other characters including a ‘short’ premaxillary rostrum (length and width subequal), five premaxillary alveoli, premaxilla-maxilla sutures parallel anterior to the external nares, frontals contact on the midline, prefrontal-frontal suture convex and gently curved medially, mandibular symphyseal region spatulate and ‘short’ (length and width subequal), prominent dorsally concave medial flange anteromedial to the articular glenoid, robust rod-like axis neural spine with a circular transverse cross section, and cervical neural spines with a mediolaterally expanded apex. The taxon shares some of these characters with earlier Hettangian rhomaleosaurids (e. g. Atychodracon, Eurycleidus), and other characters with later Toarcian rhomaleosaurids (e. g. Rhomaleosaurus sensu stricto and Meyerasaurus). Inclusion of Thaumatodracon as an additional operational taxonomic unit in several existing cladistic analyses demonstrates that it occupies a relatively derived position within Rhomaleosauridae. A morphometric multivariate analysis of Lower Jurassic rhomaleosaurids shows that Thaumatodracon is also proportionally intermediate between known rhomaleosaurid taxa. Thaumatodracon is therefore a stratigraphically and anatomically intermediate taxon that fills a gap in our knowledge of the evolution of this macro-predatory plesiosaurian clade.

Keywords: Plesiosauria, Sauropterygia, Rhomaleosauridae, Lower Jurassic, Lyme Regis


Thaumatodracon wiedenrothi
Illustration: Luzia Soares. 

 Adam S. Smith and Ricardo Araújo. 2017. Thaumatodracon wiedenrothi, A Morphometrically and Stratigraphically Intermediate New Rhomaleosaurid Plesiosaurian from the Lower Jurassic (Sinemurian) of Lyme Regis. Palaeontographica, Abt. A: Palaeozoology – Stratigraphy 4-6; 89 - 125.  DOI: 10.1127/pala/308/2017/89  

 Adam S. Smith and Ricardo Araújo. 2017. Morphometric data and phylogenetic analysis of Thaumatodracon wiedenrothiPANGAEA. DOI: 10.1594/PANGAEA.870543