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Thursday, March 10th, 2022
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| 6:05a | [Paleontology • 2022] Syllipsimopodi bideni • Fossil Coleoid Cephalopod (Cephalopoda: Coleoidea) from the Mississippian Bear Gulch Lagerstätte sheds light on early Vampyropod Evolution
Abstract We describe an exceptionally well-preserved vampyropod, Syllipsimopodi bideni gen. et sp. nov., from the Carboniferous (Mississippian) Bear Gulch Lagerstätte of Montana, USA. The specimen possesses a gladius and ten robust arms bearing biserial rows of suckers; it is the only known vampyropod to retain the ancestral ten-arm condition. Syllipsimopodi is the oldest definitive vampyropod and crown coleoid, pushing back the fossil record of this group by ~81.9 million years, corroborating molecular clock estimates. Using a Bayesian tip-dated phylogeny of fossil neocoleoid cephalopods, we demonstrate that Syllipsimopodi is the earliest-diverging known vampyropod. This strongly challenges the common hypothesis that vampyropods descended from a Triassic phragmoteuthid belemnoid. As early as the Mississippian, vampyropods were evidently characterized by the loss of the chambered phragmocone and primordial rostrum—traits retained in belemnoids and many extant decabrachians. A pair of arms may have been elongated, which when combined with the long gladius and terminal fins, indicates that the morphology of the earliest vampyropods superficially resembled extant squids.
  
Class: Cephalopoda Cuvier 1795 Subclass: Coleoidea Bather 1888 Clade: Vampyropoda von Boletzky 1992 Syllipsimopodi bideni gen. et sp. nov. Holotype. ROMIP 64897 (Royal Ontario Museum). Material. The type and only specimen was donated to the Royal Ontario Museum by B. Hawes in 1988; accession number 88-72717. There is no counterpart. Locality. Bear Gulch Limestone, Heath Formation, Big Snowy Group, Fergus County, Montana, USA. The Bear Gulch Limestone is a plattenkalk, or lithographic limestone, similar to the more famous Jurassic Solnhofen Limestone of Germany. ... Horizon. Bear Gulch Limestone, Arnsbergian E2b (~328.3–324.5 Ma), Serpukhovian (Namurian), Mississippian, Carboniferous8,18,32. Diagnosis. Coleoid with simple, nearly triangular gladius, bearing funnel-like conus and median field with median rib, but no hyperbolar zones, cone flags, or lateral reinforcements; lateral fields unlikely. Lacking chambered phragmocone, primordial rostrum, or rostrum. Ten arms bearing biserial rows of suckers but no hooks or cirri; two arms may be elongated (though this could be taphonomic). Ink sac present. Terminal median fin support and one fin pair present. Etymology. The genus name is derived from the Greek συλλήψιμος (syllípsimos) for prehensile and πόδι (pódi) for foot. The name prehensile-foot is chosen because this is the oldest known cephalopod to develop suckers, allowing the arms, which are modifications of the molluscan foot, to better grasp prey and other objects. The species name is to celebrate the recently inaugurated (at the time of submission) 46th President of the United States, Joseph R. Biden.
Christopher D. Whalen and Neil H. Landman. 2022. Fossil Coleoid Cephalopod from the Mississippian Bear Gulch Lagerstätte sheds light on early Vampyropod Evolution. Nature Communications. 13: 1107. DOI: 10.1038/s41467-022-28333-5 Octopus Ancestors Had 10 Arms, New Study Shows     | ||||||||
| 9:06a | [Arachnida • 2020] Paraphrynus pseudomexicanus • Cryptic Diversity in the Whip Spider Genus Paraphrynus (Amblypygi: Phrynidae): Integrating Morphology, Karyotype and DNA
The whip spider (Amblypygi) genus Paraphrynus Moreno, 1940 is distributed from the southern U.S.A. to the Greater Antilles and northern South America. Mexico is the diversity hotspot of the genus where many morphologically similar species occur, often in close geographical proximity. The present contribution aimed to resolve the diversity and phylogenetic relationships within the aztecus group of species, which includes the type species, Paraphrynus mexicanus (Bilimek, 1867), resulting in the description of a new species from Mexico, Paraphrynus pseudomexicanus sp. n. This is the first study to integrate morphology, karyotype, and DNA for species delimitation in whip spiders. Karyotype data have not been previously used for the taxonomy of these arachnids. Sequence analysis included seven species of the aztecus group, two other species of Paraphrynus, and an outgroup species of the putative sister genus, Phrynus Lamarck, 1801. Two nuclear genes (18S rDNA and 28S rDNA) and three mitochondrial genes (12S rDNA, 16S rDNA, and Cytochrome c Oxidase Subunit I) were analyzed phylogenetically. Hypotheses of karyotype evolution of Paraphrynus are consistent with conclusions based on the morphological and molecular data. The ancestral karyotype of the aztecus group probably consisted of a relatively low number of biarmed chromosomes. Diploid numbers decreased by cycles consisting of inversion and consequent centric fusion during the evolution of the clade comprising P. mexicanus and P. pseudomexicanus. Keywords: Arachnida, centric fusion, chromosome, evolution, inversion, molecular systematics, phylogeny, new species, taxonomy.
Genus Paraphrynus Moreno, 1940 Paraphrynus pseudomexicanus sp. n. Etymology. The new species name is a combination of the prefx pseudo-, meaning similar, and the word mexicanus, referring to the morphologically most similar species, P. mexicanus. Michael Seiter, Azucena C. Reyes Lerma, Jiří Král, Alexandr Sember, Klára Divišová, José G. Palacios Vargas, Pío A. Colmenares, Stephanie F. Loria and Lorenzo Prendini. 2020. Cryptic Diversity in the Whip Spider Genus Paraphrynus (Amblypygi: Phrynidae): Integrating Morphology, Karyotype and DNA. Arthropod Systematics & Phylogeny. 78(2): 265-285. DOI: 10.26049/ASP78-2-2020-04 | ||||||||
| 12:18p | [Crustacea • 2022] Lobothelphusa bagoensis & L. thewanica • Two New Species of the Genus Lobothelphusa Bouvier, 1917 (Decapoda: Brachyura: Potamidae) from the Pegu Range, central Myanmar
Abstract The freshwater crab genus Lobothelphusa Bouvier, 1917, is known from five species (L. crenulifera, L. calva, L. barbouri, L. floccosa, and L. woodmasoni), which are mainly distributed in Myanmar (=Burma). In this study, we describe two new species, Lobothelphusa bagoensis and L. thewanica, from the Pegu Range in central Myanmar. Characters of the carapace and male first gonopod can clearly distinguish the two new species from their congeners. Molecular data derived from a partial sequence of the mitochondrial 16S rDNA support the systematic position of the new taxa. Key words. Crustacea, Potamidae, freshwater crab, taxonomy
SYSTEMATICS Superfamily Potamoidea Ortmann, 1896 Family Potamidae Ortmann, 1896 Subfamily Potaminae Ortmann, 1896 Lobothelphusa Bouvier, 1917
Lobothelphusa bagoensis, new species Etymology. The new species is named after the administrative region in which the type locality is situated, Bago Division, Myanmar. Ecological note. These specimens were obtained from streams in hilly terrain and were dug out from mud burrows approximately 60–80 cm deep in well-drained, silty soil along the riparian zone (Fig. 7A). The eggs from three female individuals (NNU16-AG2, NNU16-AG3, SEABRI-AG4) were observed to be a bright yellow in colour and small in size (1.5–2.0 mm diameter) (Fig. 7B), and with each female carrying 253–374 eggs.
Lobothelphusa thewanica, new species Etymology. The species is named after the type locality, the township of Thewa, in the Pegu Range, Bago Division, Myanmar. Ecological note. Individuals were collected under stones and the layers of fallen leaves in the river or on its banks; the substrate consists mainly of stones and rocky rubble (Fig. 7E). Boyang Shi, Xiaoyong Chen and Hongying Sun. 2022. On Two New Species of the Genus Lobothelphusa Bouvier, 1917 (Decapoda: Brachyura: Potamidae: Potaminae) from the Pegu Range, central Myanmar. RAFFLES BULLETIN OF ZOOLOGY. 70; 65–79.  | ||||||||
| 4:07p | [PaleoOrnithology • 2022] Miotadorna catrionae • A New Species of Large Duck (Aves: Anatidae) from the Miocene of New Zealand
Abstract We describe a new species of extinct duck, Miotadorna catrionae sp. nov. (Anatidae, Tadornini, Tadorninae), based on a right humerus from the Miocene lacustrine deposits of St Bathans, Otago, New Zealand. Principal component analysis reveals that the new taxon is distinguished by its large size and relative proportions. This is the eighth and largest species of duck described from the St Bathans fossil assemblage and further underscores the global importance of this site for understanding anatid evolution. Keywords: Tadornini; Miotadorna catrionae sp. nov.; fossil; shelduck; lacustrine; Bannockburn formation
 SYSTEMATICS Class Aves Linnaeus, 1758 Order Anseriformes Wagler, 1831 Family Anatidae Leach, 1819 Subfamily Tadorninae Reichenbach, 1849: Shelducks Tribe Tadornini Reichenbach, 1849 Genus Miotadorna Worthy, Tennyson, Jones, McNamara and Douglas, 2007 Miotadorna catrionae sp. nov. Tennyson, Greer, Lubbe, Marx, Richards, Giovanardi and Rawlence Holotype: NMNZ S.47273, right humerus. Type locality: Mata Creek Site 9, St Bathans, Central Otago, 44° 52.8288′ S, 169° 50.4162′ E. NZ Fossil Record File Number H41/f0122. Bannockburn Formation, late early–earliest middle Miocene (Burdigalian–Langhian global stage, Altonian local stage), 18.7–15.9 Ma. Etymology: After N.J.R.’s mother Catriona Drummond (1954–2020) who inspired his love of natural history. Suggested English vernacular name: Catriona’s Shelduck. Diagnosis: Shelduck characterized by a robust humerus (142.5 mm long) with a wide proximal and a narrow distal end. Differs from all other anatid humeri from St Bathans in its larger size, which is comparable to that of a small goose, such as the Egyptian goose (Alopochen aegyptiaca) (e.g., NMNZ OR.29470: humerus length 142.2 mm). It specifically differs from Miotadorna sanctibathansi—the largest previously described anatid from St Bathans—in having a longer, more tapered humerus with a wider proximal end but a similar-sized distal end (Figure 2B, Appendix A). Resembles M. sanctibathansi in having an elongate shaft, a prominent capital shaft ridge directed towards the ventral side of a markedly elevated dorsal tubercle, a relatively narrow dorsal pneumotricipital fossa that does not undercut the humeral head, an elongate deltoid crest that extends well distal of the bicipital crest, and in having the attachment of the superficial pronator muscle located cranial of centre on the ventral face.  Alan J. D. Tennyson, Liam Greer, Pascale Lubbe, Felix G. Marx, Marcus D. Richards, Simone Giovanardi and Nicolas J. Rawlence. 2022. A New Species of Large Duck (Aves: Anatidae) from the Miocene of New Zealand. Taxonomy. 2(1); 136-144. DOI: 10.3390/taxonomy2010011 Something old, something new: meet St Bathans newest fossil duck sciblogs.co.nz/lost-worlds/2022/03/10/so |
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