Systematics and biogeography of the “Metacryphaeus group” Calmoniidae (Trilobita, Devonian), with comments on adaptive radiations and the geological history of the Malvinokaffric Realm

1993 ◽  
Vol 67 (4) ◽  
pp. 549-570 ◽  
Author(s):  
Bruce S. Lieberman

Phylogenetic parsimony analysis was used to classify the Siegenian–Eifelian “Metacryphaeus group” of the family Calmoniidae. Thirty-eight exoskeletal characters for 16 taxa produced a shortest-length cladogram with a consistency index of 0.49. A classification based on retrieving the structure of this cladogram recognizes nine genera: Typhloniscus Salter, Plesioconvexa n. gen., Punillaspis Baldis and Longobucco, Eldredgeia n. gen., Clarkeaspis n. gen., Malvinocooperella n. gen., Wolfartaspis Cooper, Plesiomalvinella Lieberman, Edgecombe, and Eldredge (used to represent the malvinellid clade), and Metacryphaeus Reed. The malvinellid clade is most closely related to a revised monophyletic Metacryphaeus. Typhloniscus is the basal member of the “Metacryphaeus group,” and the monotypic Wolfartaspis is sister to the clade containing the malvinellids and Metacryphaeus. Six new species are diagnosed: Punillaspis n. sp. A, “Clarkeaspis” gouldi, Clarkeaspis padillaensis, Malvinocooperella pregiganteus, Metacryphaeus curvigena, and Metacryphaeus branisai. Primitively, this group has South African and Andean affinities, and its evolutionary history suggests rapid diversification. In addition, evolutionary patterns in this group, and the distribution of character reversals, call into question certain notions about the nature of adaptive radiations. The distributions of taxa may answer questions about the number of marine transgressive/regressive cycles in the Emsian–Eifelian of the Malvinokaffric Realm.

Author(s):  
Alberto Collareta ◽  
Agatino Reitano ◽  
Antonietta Rosso ◽  
Rossana Sanfelippo ◽  
Mark Bosselaers ◽  
...  

Coronuloid barnacles are epibionts of several marine vertebrates (including cetaceans and sea turtles) as well as invertebrates, and are assigned to two families of turtle barnacles (Chelonibiidae Pilsbry, 1916 and Platylepadidae Newman & Ross, 1976) and one family of whale barnacles (Coronulidae Leach, 1817). Chelonibiids and coronulids have a scanty, albeit significant fossil record extending back to the Eocene and Pliocene, respectively; in turn, the fossil record of platylepadids is limited to a single record from the Upper Pleistocene. Here we report on an isolated carinolateral compartment of Platylepas Gray, 1825, the type genus of the family, from Lower Pleistocene (Gelasian) epibathyal deposits exposed at Milazzo (Sicily, Italy). This specimen is here designated holotype of a new species, †Platylepas mediterranea sp. nov. We argue that, like most extant members of Platylepas, †P. mediterranea sp. nov. lived partially embedded in the skin of a sea turtle. This record of an extinct platylepadid – the first from the Mediterranean region and the second worldwide – pushes back the fossil record of Platylepadidae to the lowermost Quaternary, thus possibly supporting an even earlier (e.g., Neogene) timing for the origin of this family and adding a new chapter to the evolutionary history of one of the most diverse and successful lineages of epizoic crustaceans.


2010 ◽  
Vol 84 (2) ◽  
pp. 197-215 ◽  
Author(s):  
Craig S. Scott

Cyriacotheriidae are a family of unusual small-bodied pantodonts known from the Paleocene of the Western Interior of North America. Cyriacotheriids possess a suite of dental characters similar to that of pantodonts (e.g., molar dilambdodonty, lingual molar hypoconulids), as well as several divergent features (e.g., molarized premolars, strong molar conules) that have been interpreted as “dermopteran-like.” the unusual combination of pantodont and dermopteran-like characters, combined with a limited fossil record, has made attempts at understanding the broader relationships of Cyriacotheriidae difficult. This paper reports on a new genus and two new species of cyriacotheriids from the Paleocene of Alberta, Canada, with both species significantly older than those of the only previously described cyriacotheriid, Cyriacotherium. Collectively, the dentitions of these new taxa exhibit derived characters seen in Cyriacotherium (e.g., robust molar conules, strong molar dilambdodonty) in addition to a number of plesiomorphies seen in more basal pantodonts (e.g., conspicuous molar entoconids, deep premolar ectoflexus) and, importantly, posterior premolars that are weakly molariform and non-dilambdodont. A phylogenetic analysis of the new cyriacotheriid, basal pantodonts, dermopterans, and dermopteran-like eutherians resulted in Cyriacotheriidae nesting within a monophyletic Pantodonta. the results strengthen previous hypotheses regarding the pantodont affinities of the family, and suggest that the dermopteran-like features seen in the more derived Cyriacotherium were acquired convergently. Although the discovery of new cyriacotheriids sheds light on the evolutionary history of the family, it cannot resolve the ongoing questions of pantodont origins; nonetheless, their discovery in strata of early Paleocene age indicates that significant parts of the evolutionary history of Cyriacotheriidae, and North American pantodonts more generally, have yet to be discovered.


Author(s):  
Joachim Langeneck ◽  
Michele Barbieri ◽  
Ferruccio Maltagliati ◽  
Alberto Castelli

Cirrophorus nikebianchii sp. nov. is described from brackish-water and organically enriched marine environments of the Mediterranean Sea. The new species is characterized by a very small prostomial antenna and a high number of branchiae pairs. A phylogenetic analysis carried out through the use of three molecular markers (16S rRNA, 18S rRNA and COI) supports the distinction between C. nikebianchii and C. furcatus, a closely related species with which it has been misidentified. Preliminary results obtained show that the genera Cirrophorus and Paradoneis are not reciprocally monophyletic, with uncertain relationships with the remaining genera of Paraonidae. This outcome suggests that the evolutionary history of Paraonidae is less straightforward than previously supposed. Moreover, the uncertainty about the taxonomic status of Paraonides neapolitana, type species of the genus Paraonides, makes the revamping of the taxonomy of Paraonidae more challenging. Awaiting support from studies including more species, and based on morphological and genetic data as well, we suggest to provisionally maintain the current use of Cirrophorus and Paradoneis, and to assign to Paraonella the species traditionally assigned to Paraonides.


Author(s):  
Karen A. Lowney

ABSTRACTTwo new genera and species of haplolepids (Chondrostei), Protohaplolepis scotica and Blairolepis loanheadensis, are described from the ironstones of Loanhead, Midlothian (Namurian A, E1); this represents the earliest known record of the family. Protohaplolepis scotica (= Traquair's nomen nudum “Eurylepis scoticus”) shows many features in common with Westoll's hypothetical haplolepid “common ancestor X”, and is possibly ancestral to the Haplolepis–Microhaplolepis line within the family. Blairolepis loanheadensis, known only from a skull roof, shows greater similarities to Parahaplolepis and Pyritocephalus, but differs from these genera in having separate dermopterotics and parietals. Two subfamilies, the Haplolepinae and the Parahaplolepinae, are suggested to reflect the distinct evolutionary lines within the family.A new species, Parahaplolepis westolli, is also described from Newsham, Northumberland (Westphalian B). This species shows a close resemblance to the American species Parahaplolepis tuberculata from Linton, Ohio.A brief discussion of the evolutionary history of the family is presented, along with a summary of its stratigraphical and geographical distribution.


1990 ◽  
Vol 3 (1) ◽  
pp. 145
Author(s):  
DJ Colgan

This paper is a review of the use of information regarding the presence of duplicate genes and their regulation in systematics. The review concentrates on data derived from protein electrophoresis and restriction fragment length polymorphism analysis. The appearance of a duplication in a subset of a group of species implies that the members of the subset belong to the same clade. Suppression of the duplication may render this clade apparently paraphyletic, but may itself be informative of relations within the lineage through patterns of loss of expression in all, or some tissues, or through restrictions of the formation of functional heteropolymers in polymeric enzymes. Examples are given of studies which have used such information to establish phylogenetic hypotheses at the family level, to identify an auto- or allo-polyploid origin of polyploid species and to determine whether there have been single or multiple origins of such species. The likelihood of homoplasy in the patterns of appearance and regulation of duplicates depends on the molecular basis of the duplication. In particular, the contrast between the expected consequences of tandem duplication and the expression of pseudogenes emphasises the value of determining the mechanism of the original duplication. Many instances of sporadic gene duplication are now known, and polyploidisation is a common event in the evolutionary history of both plants and animals. So the opportunities to discover duplicationrelated characters will arise in many systematic studies. A program is presented to increase the chances that such useful information will be recognisable during the studies.


2005 ◽  
Vol 1 (3) ◽  
pp. 291-295 ◽  
Author(s):  
Jennifer A Leonard ◽  
Nadin Rohland ◽  
Scott Glaberman ◽  
Robert C Fleischer ◽  
Adalgisa Caccone ◽  
...  

Twenty years ago, the field of ancient DNA was launched with the publication of two short mitochondrial (mt) DNA sequences from a single quagga ( Equus quagga ) museum skin, an extinct South African equid ( Higuchi et al . 1984 Nature 312 , 282–284). This was the first extinct species from which genetic information was retrieved. The DNA sequences of the quagga showed that it was more closely related to zebras than to horses. However, quagga evolutionary history is far from clear. We have isolated DNA from eight quaggas and a plains zebra (subspecies or phenotype Equus burchelli burchelli ). We show that the quagga displayed little genetic diversity and very recently diverged from the plains zebra, probably during the penultimate glacial maximum. This emphasizes the importance of Pleistocene climate changes for phylogeographic patterns in African as well as Holarctic fauna.


Author(s):  
Carol Simon ◽  
Guillermo San Martín ◽  
Georgina Robinson

Two new species of South African Syllidae of the genusSyllisLamarck, 1818 are described.Syllis unzimasp. nov. is characterized by having unidentate compound chaetae with long spines on margin, a characteristic colour pattern and its reproduction by vivipary. Vivipary is not common among the polychaetes, but most representatives occur in the family Syllidae Grube, 1850 (in five otherSyllisspecies, two species ofDentatisyllisPerkins, 1981 and two species ofParexogoneMesnil & Caullery, 1818).Syllis unzimasp. nov. differs from the other viviparous species in having large broods (>44 juveniles) which develop synchronously. Development of the juveniles is similar to that of free-spawningSyllisspecies, but the appearance of the first pair of eyespots and the differentiation of the pharynx and proventricle occur later inS. unzima.Syllis amicarmillarissp. nov., is characterized by having an elongated body with relatively short, fusiform dorsal cirri and the presence of one or two pseudosimple chaeta on midbody parapodia by loss of blade and enlargement of shaft.Syllis unzimasp. nov. was found in high densities on culturedHolothuria scabraJaeger, 1833 with single specimens found on a culturedCrassostrea gigasThunberg, 1793 and on coralline algae, respectively, whileS. amicarmillariswas found mainly in sediment outside an abalone farm and less frequently on culturedHaliotis midaeLinnaeus, 1758. We discuss the possible benefits of the association withH. scabratoS. unzimasp. nov.


Zootaxa ◽  
2022 ◽  
Vol 5091 (4) ◽  
pp. 501-545
Author(s):  
YI-FENG ZHANG ◽  
LING-ZENG MENG ◽  
ROGER A. BEAVER

The powder post beetles (Coleoptera: Bostrichidae) (except Lyctinae) of Yunnan Province in Southwest China are reviewed for the first time. Keys to twenty-six genera and fifty-two species from the Yunnan region are provided. One new genus and seven new species are described: Dinoderus (Dinoderastes) hongheensis sp. nov., Dinoderus (Dinoderastes) nanxiheensis sp. nov., Gracilenta yingjiangensis gen. nov., sp. nov., Calonistes vittatus sp. nov., Calophagus colombiana sp. nov., Xylodrypta guochuanii sp. nov. and Xylodrypta zhenghei sp. nov.. Fourteen species are recorded in China for the first time. The bostrichid fauna of Yunnan is compared with those of the neighbouring bio-geographically related Southeast Asian and Himalayan regions. The fauna has a close affinity with that of tropical Southeast Asia and a much weaker relationship with the Palearctic region. The differences with the Himalayas may reflect the separate evolutionary and complex geological history of the two areas.


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