The strophomenide brachiopod Ahtiella Öpik in the Ordovician of Gondwana and the early history of the plectambonitoids

2018 ◽  
Vol 92 (5) ◽  
pp. 768-793 ◽  
Author(s):  
Juan L. Benedetto
Keyword(s):  
New Species ◽  
Fossil Record ◽  
Species Level ◽  
Early History ◽  
Northwestern Argentina ◽  
Higher Taxa ◽  
History Of ◽  
Volcaniclastic Rocks ◽  
Short Time ◽  
Volcaniclastic Succession

AbstractThe Precordilleran species Ahtiella argentina Benedetto and Herrera, 1986 is redescribed and illustrated and Monorthis coloradoensis Benedetto, 1998b from northwestern Argentina is reassigned to the genus Ahtiella Öpik, 1932. Ahtiella famatiniana new species from volcaniclastic rocks of the Famatina range (western Argentina) and Ahtiella tunaensis new species from the Precordillera basin (Cuyania terrane) are proposed. Paleogeographic and stratigraphic evidence strongly suggests that Ahtiella originated in the Andean region of Gondwana to further migrate to Avalonia, Baltica, and Cuyania. Contrary to previous assumptions, the fossil record from the Famatina volcaniclastic succession suggests that the plectambonitoid Ahtiella famatiniana n. sp. evolved from the hesperonomiid orthoid Monorthis transversa Benedetto, 2003 that always occurs in the underlying strata. Phylogenetic analysis of Ahtiella species shows that A. famatiniana n. sp. and the Peruvian A. zarelae Villas in Gutiérrez-Marco and Villas, 2007 are not only the earliest species of the genus but also are morphologically intermediate between Monorthis Bates, 1968 and the later and more derived species of Ahtiella from Baltica and Cuyania. If, as empirical evidence presented here shows, Ahtiella originated from Monorthis through a series of minor transformations, then the impressive morphological gap between orthides and strophomenides was bridged through short-time cladogenesis events, suggesting that it might not have a definite discontinuity between the species level evolution and the origin of higher taxa (macroevolution).UUID: http://zoobank.org/4b8c5442-ea2c-41b2-97f7-4c0a8b0384a2

scholarly journals Historical evolutionary information in the traditional Linnean hierarchy

1992 ◽  
Vol 6 ◽  
pp. 16-16 ◽  
Author(s):  
Richard K. Bambach ◽  
J. John Sepkoski
Keyword(s):  
Fossil Record ◽  
Latitudinal Gradients ◽  
Evolutionary Information ◽  
Simulation Studies ◽  
Biological Organization ◽  
Diversity Patterns ◽  
Higher Taxa ◽  
History Of ◽  
The Stability ◽  
And Function

The first two ranks above the species level in the traditional Linnean hierarchy — the genus and family — are species based: genera have been erected to unify groups of morphologically similar, closely related species and families have been erected to group genera recognized as closely related because of the shared morphologic characteristics of their species. Diversity patterns of traditional genera and families thus appear congruent with those of species in (a) the Recent (e. g., latitudinal gradients in many groups), (b) compilations of all marine taxa for the entire Phanerozoic (including the stage level), (c) comparisons through time within individual taxa (e. g., Foraminifera, Rugosa, Conodonta), and (d) simulation studies. Genera and families often have a more robust fossil record of diversity than species, especially for poorly sampled groups (e. g., echinoids), because of the range-through record of these polytypic taxa. Simulation studies indicate that paraphyly among traditionally defined taxa is not a fatal problem for diversity studies; in fact, when degradation of the quality of the fossil record is modelled, both diversity and rates of origination and extinction are better represented by including paraphyletic taxa than by restricting data to monophyletic clades. This result underscores the utility of traditional rank-based analyses of the history of diversity.In contrast, the three higher ranks of the Linnean hierarchy — orders, classes and phyla — are defined and recognized by key character complexes assumed to be rooted deep in the developmental program and, therefore, considered to be of special significance. These taxa are unified on the basis of body plan and function, not species morphology. Even if paraphyletic, recognition of such taxa is useful because they represent different functional complexes that reflect biological organization and major evolutionary innovations, often with different ecological capacities. Phanerozoic diversity patterns of orders, classes and phyla are not congruent with those of lower taxa; the higher groups each increased rapidly in the early Paleozoic, during the explosive diversification of body plans in the Cambrian, and then remained stable or declined slightly after the Ordovician. The diversity history of orders superficially resembles that of lower taxa, but this is a result only of ordinal turnover among the Echinodermata coupled with ordinal radiation in the Chordata; it is not a highly damped signal derived from the diversity of species, genera, or families. Despite the stability of numbers among post-Ordovician Linnean higher taxa, the diversity of lower taxa within many of these Bauplan groups fluctuated widely, and these diversity patterns signal embedded ecologic information, such as differences in flexibility in filling or utilizing ecospace.Phylogenetic analysis is vital for understanding the origins and genealogical structure of higher taxa. Only in such fashion can convergence and its implications for ecological constraints and/or opportunities be understood. But blind insistence on the use of monophyletic classifications in all studies would obscure some of the important information contained in traditional taxonomic groupings. The developmental modifications that characterize Linnean higher taxa (and traditionally separate them from their paraphyletic ancestral taxa) provide keys to understanding the role of shifting ecology in macroevolutionary success.

Long/Short Term Influences on Change

1999 ◽  
Vol 9 ◽  
pp. 309-318
Author(s):  
Kaustuv Roy
Keyword(s):  
Fossil Record ◽  
The Other ◽  
Short Term ◽  
Geologic Time ◽  
Number Of Species ◽  
Higher Taxa ◽  
Terrestrial Habitats ◽  
History Of ◽  
Using Data ◽  
Over Time

Change has been the rule in the history of life. Mammals today dominate the terrestrial habitats where dinosaurs once held sway. In modern oceans, ecologists can study many species of arthropods, but trilobites are long gone. Using data from the fossil record, David Raup estimated that only about one in a thousand species that ever lived on this planet is still alive today (Raup, 1991). On the other hand, the number of species and higher taxa has increased steadily over geologic time. Thus the history of life is essentially a history of turnover of species, lineages and higher taxa over time.

A new species of Australian freetail bat Mormopterus eleryi sp. nov. (Chiroptera: Molossidae) and a taxonomic reappraisal of M. norfolkensis (Gray)

Zootaxa ◽  
2008 ◽  
Vol 1875 (1) ◽  
pp. 1 ◽  
Author(s):  
TERRY REARDON ◽  
MARK ADAMS ◽  
NORM MCKENZIE ◽  
PAULINA JENKINS
Keyword(s):  
New Species ◽  
Species Level ◽  
Glans Penis ◽  
Museum Specimens ◽  
Echolocation Call ◽  
Norfolk Island ◽  
History Of ◽  
Central Australia ◽  
The Relationship ◽  
A New Species

The species-level taxonomy of Australian Mormopterus has a long history of uncertainty. In this paper we review in detail the historic problems associated with determining the relationship between the norfolkensis holotype (allegedly from Norfolk Island) and forms occurring on mainland Australia. Using external and cranial characters, we establish that the holotype is conspecific with mainland specimens and we provide a redescription of the species. We also describe a new species, Mormopterus eleryi sp. nov. from central Australia. Updated allozyme profiles (a total of 40 putative loci) show that M. norfolkensis and M. eleryi sp. nov. diverge from one another at an average of 49% fixed differences and each diverge from the ‘planiceps-beccarii-loriae’ complex at an average of 48% and 45% fixed differences respectively. While both species are readily diagnosable by external and cranial features, they are especially distinctive in the morphology of the upper molars and glans penis. Echolocation call profiles as recorded by ANABAT bat detectors also show both species to have unique search phase calls compared to other Australian Mormopterus species. Both M norfolkensis and M. eleryi sp. nov. are known from less than 30 museum specimens each.

Taxonomic survivorship curves and Van Valen's Law

Paleobiology ◽  
1975 ◽  
Vol 1 (1) ◽  
pp. 82-96 ◽  
Author(s):  
David M. Raup
Keyword(s):  
Fossil Record ◽  
Species Level ◽  
Extinction Rate ◽  
Survivorship Analysis ◽  
Survivorship Curve ◽  
Extinction Rates ◽  
Higher Taxa ◽  
Total Life ◽  
Adaptive Zone

As Van Valen has demonstrated, the taxonomic survivorship curve is a valuable means of investigating extinction rates in the fossil record. He suggested that within an adaptive zone, related taxa display stochastically constant and equal extinction rates. Such a condition is evidenced by straight survivorship curves for species and higher taxa. Van Valen's methods of survivorship analysis can be improved upon and several suggestions are presented. With proper manipulation of data, it is possible to pool the information from extinct and living taxa to produce a single survivorship curve and therefore a single estimate of extinction rate. If extinction rate is constant at the species level (producing a straight survivorship curve), higher taxa in the same group should be expected to have convex survivorship curves. The constancy of extinction rates (here termed Van Valen's Law) can and should be tested rigorously. Several methods are available, of which the Total Life method of Epstein is particularly effective.

The first diplatyid earwig in Tertiary amber (Dermaptera: Diplatyidae): A new species from Miocene Mexican amber

2013 ◽  
Vol 44 (2) ◽  
pp. 157-166 ◽  
Author(s):  
Andrew J. Ross ◽  
Michael S. Engel
Keyword(s):  
New Species ◽  
Adult Female ◽  
Fossil Record ◽  
Evolutionary History ◽  
History Of ◽  
A New Species

The first earwig (Dermaptera) to be described from Mexican (Miocene) amber is named Haplodiplatys crightoni Ross & Engel sp.n., represented by an adult female and constituting the second record of the basal family Diplatyidae in the fossil record. Brief comments are made regarding the biogeographic implications of the fossil and the evolutionary history of Diplatyidae.

scholarly journals The oldest platylepadid turtle barnacle (Cirripedia, Coronuloidea): a new species of Platylepas from the Lower Pleistocene of Italy

2019 ◽  
Author(s):  
Alberto Collareta ◽  
Agatino Reitano ◽  
Antonietta Rosso ◽  
Rossana Sanfelippo ◽  
Mark Bosselaers ◽  
...  
Keyword(s):  
New Species ◽  
Fossil Record ◽  
Mediterranean Region ◽  
Evolutionary History ◽  
Sea Turtle ◽  
Upper Pleistocene ◽  
The Family ◽  
Lower Pleistocene ◽  
History Of ◽  
A New Species

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.

scholarly journals A revised global biogeography of turtles

2015 ◽  
Author(s):  
Walter G. Joyce ◽  
Márton Rabi
Keyword(s):  
Middle Jurassic ◽  
Fossil Record ◽  
Phylogenetic Analyses ◽  
Sensu Stricto ◽  
Early History ◽  
Marine Turtles ◽  
Biogeographic History ◽  
Global Presence ◽  
History Of ◽  
Phylogenetic Hypotheses

Background. Over the course of the last decades, much effort has gone into unraveling the biogeographic history of turtles, but while much progress has been achieved in resolving post- Jurassic dispersal events, traditional phylogenetic hypotheses have yielded incongruous results in regards to the early history of the group. Methods. We re-evaluate the fossil record of turtles in context of recent phylogenetic analyses and fossil finds, including the extensive record of fragmentary but diagnostic remains. Given that near-coastal and marine turtles readily disperse across aquatic barriers, a broad set of neritic to pelagic groups were disregarded from consideration. Significant disagreement still exists among current phylogenetic hypotheses and we therefore place much effort into tracing the fossil record of unambiguously monophyletic groups. We finally employed molecular backbone constraints, given that the molecular phylogenies are more consistent with the fossil record than current, morphological phylogenies. Results. Among derived, aquatic turtles, we recognize four clades that can be traced back to discrete biogeographic centers: Paracryptodira in North America and Europe, Pan- Cryptodira in Asia, Pan-Pelomedusoides in northern Gondwanan landmasses and Pan- Chelidae in southern Gondwanan landmasses. This pattern is partially mirrored by three clades of primarily terrestrial, basal turtles: Solemydidae in North American and Europe, Sichuanchelyidae in Asia, and Meiolaniformes sensu stricto in southern Gondwanan landmasses. Although the exact interrelationships of these clades remain unclear, most can be traced back to the Middle Jurassic. Discussion. The conclusion that the two primary lineages of pleurodires and paracryptodires can be traced back to mutually exclusive land masses is not novel, but the realization that the early history of pan-cryptodires is restricted to Asia has not been realized previously, because traditional phylogenies implied an early, global presence of pan-cryptodires. The timing of the origin of the three primary clades of derived turtles (i.e., Pan-Pleurodira, Pan-Cryptodira, and Paracryptodira) correlates with the opening of the central Atlantic and the formation of the Turgai Strait in the Middle Jurassic, somewhat later than predicted by molecular calibration studies. The primary diversity of extant turtles therefore appears to have been driven by vicariance. A similar hypothesis could also be formulated for the three clades of basal turtles that survive at least into the Late Cretaceous, but given that their combined monophyly remains uncertain, it is unclear if their diversity was also driven by vicariance, or if they emulate a vicariance-like pattern. Although most groups remained within their primary geographic range throughout their evolutionary history, the dominant vicariance signal was thoroughly obfuscated by rich dispersal from littoral to marine turtles and crown cryptodires.

Long / Short Term Influences on Change

2002 ◽  
Vol 11 ◽  
pp. 249-256
Author(s):  
Kaustuv Roy
Keyword(s):  
Fossil Record ◽  
The Other ◽  
Short Term ◽  
Geologic Time ◽  
Number Of Species ◽  
Higher Taxa ◽  
Terrestrial Habitats ◽  
History Of ◽  
Using Data ◽  
Over Time

Change has been the rule in the history of life. Mammals today dominate the terrestrial habitats where dinosaurs once held sway. In modern oceans, ecologists can study many species of arthropods, but trilobites are long gone. Using data from the fossil record, David Raup estimated that only about one in a thousand species that ever lived on this planet is still alive today (Raup, 1991). On the other hand, the number of species and higher taxa has increased steadily over geologic time. Thus the history of life is essentially a history of turnover of species, lineages, and higher taxa over time.

New cyriacotheriid pantodonts (Mammalia, Pantodonta) from the Paleocene of Alberta, Canada, and the relationships of Cyriacotheriidae

2010 ◽  
Vol 84 (2) ◽  
pp. 197-215 ◽  
Author(s):  
Craig S. Scott
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Fossil Record ◽  
Evolutionary History ◽  
New Genus ◽  
The Family ◽  
Two New Species ◽  
Unusual Combination ◽  
Early Paleocene ◽  
History Of

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.

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