New material and systematic re-evaluation ofMedusaceratops lokii(Dinosauria, Ceratopsidae) from the Judith River Formation (Campanian, Montana)

2017 ◽  
Vol 92 (2) ◽  
pp. 272-288 ◽  
Author(s):  
Kentaro Chiba ◽  
Michael J. Ryan ◽  
Federico Fanti ◽  
Mark A. Loewen ◽  
David C. Evans
Keyword(s):  
Phylogenetic Analysis ◽  
Systematic Revision ◽  
New Material ◽  
Judith River Formation

AbstractMedusaceratops lokiiRyan, Russell, and Hartman, 2010 is an enigmatic taxon of ceratopsid represented by partial parietals from the Mansfield bonebed in the Campanian Judith River Formation, Montana. Originally, all ceratopsid material collected from this bonebed was referred to the centrosaurine ceratopsidAlbertaceratops, but subsequently two parietals were designated the types of the chasmosaurine,M.lokii, in part, because they were interpreted to have three epiparietals bilaterally. Here we describe new material from the bonebed that allows a systematic revision of the taxon. A revised reconstruction of the frill, informed by newly discovered parietals, reveals thatM.lokiihad a broad midline ramus and at least five epiparietals (ep) around the margin of the frill, both traits that are characteristic of Centrosaurinae. From medial to lateral, the epiparietal ornamentation consists of a small, variably procurving epiparietal (ep 1), an anterolaterally curving pachyostotic hook (ep 2), a smaller pachyostoic process (ep 3), and two small triangular epiparietals (ep 4 and 5). A phylogenetic analysis of ceratopsids, which is the first to includeMedusaceratops, indicates thatM.lokiiis a unique, early centrosaurine ceratopsid taxon that is more closely related to Centrosaurini and Pachyrhinosaurini than Nasutoceratopsini. No unequivocal chasmosaurine bones or diagnostic material from any other ceratopsid could be identified from the Mansfield bonebed, suggesting that it represents one of the oldest occurrences of a monodominant accumulation of a centrosaurine ceratopsid on record.

A revision of Xinjiangchelys oshanensis (Ye, 1973), and new material from the Middle Jurassic of Lufeng, Yunnan Province, China

2015 ◽  
Vol 186 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Haiyan Tong ◽  
Zhiming Dong ◽  
Tao Wang
Keyword(s):  
Middle Jurassic ◽  
Yunnan Province ◽  
Shell Morphology ◽  
Single Specimen ◽  
Systematic Revision ◽  
Additional Information ◽  
New Material

Abstract Xinjiangchelys oshanensis (Ye, 1973) was originally described as Plesiochelys oshanensisYe, 1973 from the Jurassic Upper Lufeng series of Eshan, Yunnan Province, China. The species was based on a single specimen (IVPP V4444), a damaged shell with articulated carapace and plastron. This species was later referred to as Xinjiangchelys? oshanensis and X. oshanensis respectively, but has never been revised and often overlooked in the studies of Asian Mesozoic turtles. In this paper, we provide the systematic revision of X. oshanensis (Ye, 1973) after new restoration of the specimen. Five additional shells from the Middle Jurassic Chuanjie Formation of Lufeng, Yunnan Province, China are referred to this species. Our study confirms the validity of the species and its assignment to the genus Xinjiangchelys. The study of the new material completes the shell morphology of X. oshanensis and provides additional information about its age.

A redefinition of the genus Troglocharinus Reitter, 1908, with description of new species (Coleoptera, Leiodidae, Cholevinae, Leptodirini)

Zootaxa ◽  
2021 ◽  
Vol 4926 (2) ◽  
pp. 151-188
Author(s):  
JAVIER FRESNEDA ◽  
VALERIA RIZZO ◽  
JORDI COMAS ◽  
IGNACIO RIBERA
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Valid Species ◽  
Distribution Area ◽  
Undescribed Species ◽  
Separate Species ◽  
Male And Female ◽  
New Material

We redefine the genus Troglocharinus Reitter, 1908 based on a phylogenetic analysis with a combination of mitochondrial and molecular data. We recovered the current Speonomites mengeli (Jeannel, 1910) and S. mercedesi (Zariquiey, 1922) as valid, separate species within the Troglocharinus clade, not directly related to Speonomites Jeannel, 1910, a finding corroborated by a detailed study of the male and female genitalia. In consequence, we reinstate Speonomus mercedesi Zariquiey, 1922 stat. nov. as a valid species, transfer both of them to the genus Troglocharinus, T. mengeli (Jeannel, 1910) comb. nov. and T. mercedesi (Zariquiey, 1922) comb. nov., and redescribe the genus. The study of new material from the distribution area of the former S. mengeli revealed the presence of two undescribed species, T. sendrai sp. nov. and T. fadriquei sp. nov., which we describe herein. We designate the lectotype of Speonomus vinyasi Escolà, 1971 to fix its identity, as among its syntypes there are two different species. In agreement with the results of the phylogenetic analyses we establish the synonymy between the genus Speonomites and Pallaresiella Fresneda, 1998 syn. nv. 

Taxonomic revision and preliminary phylogenetic analysis of the subgenus Megalostomis (Scaphigenia) Lacordaire (Coleoptera: Chrysomelidae)

2007 ◽  
Vol 38 (3) ◽  
pp. 335-359 ◽  
Author(s):  
Sergio Roig-Juñent ◽  
Martha Domínguez ◽  
Federico Agrain
Keyword(s):  
Phylogenetic Analysis ◽  
Arid Regions ◽  
Cladistic Analysis ◽  
Taxonomic Revision ◽  
Morphological Characters ◽  
Distribution Data ◽  
Species Status ◽  
Systematic Revision ◽  
Male And Female ◽  
Preliminary Phylogenetic Analysis

AbstractThe subgenus M. (Scaphigenia) Lacordaire includes six species distributed in arid regions of South America. A systematic revision of this subgenus is presented, including re-descriptions and an update of distribution data of the six species. A preliminary cladistic analysis is performed to test the relationships among the species of the subgenus and if the morphological characters used are suitable. A key is presented to separate the seven subgenera of Megalostomis Chevrolat as well as a key for the species of the subgenus M. (Scaphigenia). Male aedeagus internal sac of the nine studied taxa are described and illustrated. This constitutes the first internal sac descriptions for members of this subtribe and could help clarify the homology of such structures within Cryptocephalinae. M. (S) consimilis Achard is reassigned to the species status on the base of genitalic characters. The cladistic analysis was done using forty-one characters from adult external morphology and male and female genitalia. Two species of two different subgenera of Megalostomis: M. (Megalostomis), and M. (Heterostomis) Lacordaire, and one representative of the genus Themesia Lacordaire were selected as out groups. Results were obtained by implicit enumeration using parsimony software. Three equally parsimonious trees were obtained of 45 steps, Ri=0.952, and Ci= 0.941. Support of each group was evaluated by Jacknifing, Bootstrap and Bremer values. Relationships between species are discussed.

Corrigendum to: Systematic revision, phylogeny and host plant associations of the Australian endemic genus Mcateella Drake (Hemiptera:Heteroptera:Piesmatidae)

2012 ◽  
Vol 26 (4) ◽  
pp. 434
Author(s):  
Michael A. Elias ◽  
Gerasimos Cassis
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Host Plant ◽  
Sister Taxon ◽  
Plant Analysis ◽  
Systematic Revision ◽  
Endemic Genus ◽  
Plant Associations ◽  
Wide Range ◽  
Stridulatory Apparatus

A systematic revision of Mcateella is given including the description of seven new species: M. austera, sp. nov., M. coolgardie, sp. nov., M. esperancensis, sp. nov., M. exocarposa, sp. nov., M. kwoki, sp. nov., M. reidi, sp. nov. and M. schuhi, sp. nov. The following species are redescribed: M. elongata Hacker M. gibber Drake, M. interioris Hacker and M. splendida Drake. Mcateella is defined as a monophyletic group on the basis of clavate guard setae and the stridulatory apparatus. Phylogenetic analysis of the Piesmatidae recognised Eopiesma as the sister-taxon relative to the remaining extant Piesmatidae. The ingroup relationships of Mcateella contained one polytomy. Miespa was found to be the sister taxon to Mcateella, positing a transantarctic relationship. Host plant analysis indicates that Mcateella are not all Acacia specialists as stated in the literature but feed on a wide range of angiosperms.

The skull of Nimbacinus dicksoni (Thylacinidae : Marsupialia)

2001 ◽  
Vol 49 (5) ◽  
pp. 487 ◽  
Author(s):  
S. Wroe ◽  
A. Musser
Keyword(s):  
Phylogenetic Analysis ◽  
The Other ◽  
Sister Taxon ◽  
Recent Attempt ◽  
Early Eocene ◽  
Late Oligocene ◽  
Parsimony Analysis ◽  
Anatomical Data ◽  
The Family ◽  
New Material

The exceptionally well preserved skull and mandible of the Miocene thylacinid Nimbacinus dicksoni is described. Phylogenetic analysis supports the contention that, within the family, the dentition of N. dicksoni is unspecialised, less derived than the recent Thylacinus cynocephalus for at least 12 features. However, relatively few cranial specialisations evident in T. cynocephalus clearly distinguish it from N. dicksoni. These two taxa share at least three derived cranial features not present in the most generalised thylacinid known from significant cranial material, the late Oligocene Badjcinus turnbulli. On the other hand, where comparison is possible, even the most specialised thylacinid, T. cynocephalus, is plesiomorphic for at least 10 cranial features common to modern dasyurids and five present in the Miocene dasyurid, Barinya wangala. Two character states found in thylacinids are more derived than in B. wangala. Relative to the remaining dasyuromorphian family, Myrmecobiidae, represented by the monotypic Myrmecobius fasciatus, thylacinids are derived for five cranial features and plesiomorphic for five. It appears that despite considerable anatomical diversity among the dentitia of thylacinids and the presence of many highly specialised dental features in some species, the crania of thylacinids have remained remarkably conservative. Even with respect to dentitia, in terms of overall similarity, the Miocene Thylacinus macknessiand late Oligocene material referred to Thylacinus does not differ greatly from the recently extinct T. cynocephalus. It now also seems probable that T. macknessi was also very similar to T. cynocephalus with respect to cranial anatomy. Numerical parsimony analysis incorporating this new material produced moderate bootstrap and Bremer support for a monophyletic Thylacinidae. In this same treatment strict consensus placed Myrmecobius fasciatus as the sister taxon to Thylacinidae–Dasyuridae, but bootstrap and Bremer support was lacking. Both of these results are contra those of the most recent attempt to resolve dasyuromorphian relationships using numerical parsimony and anatomical data. In the present analysis, the early Eocene Australian taxon, Djarthia murgonensis, fell outside a clade inclusive of all other Australian taxa and was monophyletic with the borhyaeniod, Mayulestes ferox. This latter relationship is based on limited material, poorly supported and considered highly unlikely, but it does strengthen the argument that formal placement of D. murgonensis beyond the level of Marsupialia incertae sedisis unwarranted at present.

Sign in / Sign up

Export Citation Format

Share Document