Evolution and Radiation of Mammals in the Eocene, and the Diversification of Modern Orders

The Eocene was an especially interesting and important time in the history of mammals. Whereas the Paleocene witnessed the rise of mammals from their previously subordinate position among terrestrial vertebrates, it was during the Eocene that the second major radiation of eutherian mammals took place. Many of the modern orders diversified and achieved dominance on land, and mammals even began to invade the seas and take to the air. By the late Eocene, this explosive radiation had produced the greatest ordinal diversity of mammals known at any time in their history (Lillegraven, 1972). If we could travel back to the Paleocene, we would see few familiar mammals; most belonged to archaic groups that long ago became extinct. But a visitor to the Eocene (given wide latitude in space and time, of course) might recognize many of the denizens of Eocene forests and floodplains—bats, prosimian primates, squirrel-like rodents, rabbits, moles, armadillos, and miniature hoofed animals resembling mouse deer. Along the shore, our hypothetical Eocene naturalist might spot a whale or a primitive sea cow. A closer look would reveal that these animals differed in many ways from living forms, of course, but the resemblances are real and, in some cases, striking. In fact, at least 10 orders of mammals alive today appeared in the fossil record for the first time, or experienced major radiations of modern groups, in the Eocene. Not all Eocene mammals belonged to modern orders, however. There was still a considerable proportion of archaic mammals, many representing lines that had begun in the Paleocene or, in some instances, before. And some of them were highly successful too.

The origin and early radiation of terrestrial vertebrates

10.1017/s0022336000017248 ◽

2001 ◽

Vol 75 (6) ◽

pp. 1202-1213 ◽

Cited By ~ 16

Author(s):

Robert L. Carroll

Keyword(s):

Fossil Record ◽

Early Carboniferous ◽

Late Devonian ◽

Lower Carboniferous ◽

Major Transitions ◽

Terrestrial Vertebrates ◽

History Of ◽

Paleozoic Tetrapods ◽

Early Radiation ◽

Ways Of Life

The origin of tetrapods from sarcopterygian fish in the Late Devonian is one of the best known major transitions in the history of vertebrates. Unfortunately, extensive gaps in the fossil record of the Lower Carboniferous and Triassic make it very difficult to establish the nature of relationships among Paleozoic tetrapods, or their specific affinities with modern amphibians. The major lineages of Paleozoic labyrinthodonts and lepospondyls are not adequately known until after a 20–30 m.y. gap in the Early Carboniferous fossil record, by which time they were highly divergent in anatomy, ways of life, and patterns of development. An even wider temporal and morphological gap separates modern amphibians from any plausible Permo-Carboniferous ancestors. The oldest known caecilian shows numerous synapomorphies with the lepospondyl microsaur Rhynchonkos. Adult anatomy and patterns of development in frogs and salamanders support their origin from different families of dissorophoid labyrinthodonts. The ancestry of amniotes apparently lies among very early anthracosaurs.

Reinterpretation of the Cambrian ‘bryozoan’ Pywackia as an octocoral

10.1666/13-029 ◽

2013 ◽

Vol 87 (6) ◽

pp. 984-990 ◽

Cited By ~ 24

Author(s):

Paul D. Taylor ◽

Björn Berning ◽

Mark A. Wilson

Keyword(s):

Fossil Record ◽

Evolutionary History ◽

Alternative Hypothesis ◽

Skeletal Structure ◽

Original Material ◽

Southern Mexico ◽

Upper Cambrian ◽

History Of ◽

First Time ◽

Scanning Electron

Pywackia baileyi Landing in Landing et al., 2010, from the upper Cambrian Yudachica Member of Oaxaca State, southern Mexico, consists of small, phosphatic, proximally tapering cylindrical rods covered by shallow polygonal calices. The bryozoan-like morphology of this fossil prompted its interpretation as the first bryozoan known from the Cambrian. However, restudy of some of the original material, employing scanning electron microscopy for the first time, questions the assignment of Pywackia to the Bryozoa. Striking similarities between Pywackia and the modern pennatulacean octocoral Lituaria lead to an alternative hypothesis interpreting Pywackia an early fossil octocoral. While Pywackia is probably not a true pennatulacean, a group with a definitive fossil record stretching back only to the Late Cretaceous, it can be envisaged as having had a similar skeletal structure and ecology to Lituaria, the rods representing mineralized axes of tiny colonies that lived with their proximal ends buried in the sediment and distal ends covered by feeding polyps. Landing et al. (2010) considered the phosphatic composition of Pywackia specimens to be the result of diagenetic replacement, but the evidence is equivocal. If Pywackia had a primary phosphatic skeleton, this would support the hypothesized existence of phosphatic biomineralization early in the evolutionary history of Cnidaria, as well as providing further evidence that Pywackia is not a bryozoan.

Shakespeare's Existentials

10.12737/1064939 ◽

2021 ◽

Author(s):

Pavel Gorohov

Keyword(s):

Human Life ◽

History Of Philosophy ◽

Close Connection ◽

Philosophical Literature ◽

Space And Time ◽

Wide Range ◽

The World ◽

History Of ◽

For the first time in the Russian historical and philosophical literature, the monograph attempts to comprehensively consider the philosophical views of the great playwright and thinker. Shakespeare is presented as a philosopher who considered in his masterpieces the relation of man to the world through a series of"borderline situations". Shakespeare not only anticipated the existentialist philosophers, but also appeared in his work as the greatest philosopher-anthropologist. He reflects on the essence of nature, space and time only in close connection with thoughts about human life. For a wide range of readers interested in the history of philosophy and Shakespeare studies.

Belinurus Bronn, 1839 (Chelicerata, Xiphosura) has priority over Bellinurus Pictet, 1846

10.1017/jpa.2021.53 ◽

2021 ◽

pp. 1-4

Author(s):

James C. Lamsdell ◽

Matthew E. Clapham

Keyword(s):

Nineteenth Century ◽

Fossil Record ◽

Type Species ◽

Anatomical Study ◽

Publication Date ◽

Taxonomic History ◽

Horseshoe Crabs ◽

History Of ◽

First Time ◽

Complete History

In the first half of the nineteenth century, a marked shift occurred in our understanding and treatment of the chelicerate fossil record, with the differentiation and recognition of entirely extinct genera for the first time. At the heart of this taxonomic revolution were the Eurypterida (sea scorpions) and Xiphosura (horseshoe crabs), although both groups were in fact considered crustaceans until Lankester's (1881) seminal comparative anatomical study of the extant xiphosuran Limulus Müller, 1785 and modern scorpions. The oldest available eurypterid genus is Eurypterus deKay, 1825; the oldest available fossil arachnid genus name is that of the scorpion Cyclophthalmus Corda, 1835. However, there has been considerable historical confusion over the oldest available fossil xiphosuran genus name, which has been recognized alternately as Belinurus König (with a publication date of either 1820 or 1851) or the synonymous Bellinurus Pictet, 1846. Most recent treatments (e.g., Selden and Siveter, 1987; Anderson and Selden, 1997; Anderson et al., 1997; Lamsdell, 2016, 2021; Bicknell and Pates, 2020) have favored Bellinurus Pictet, 1846 as the available name; however, Haug and Haug (2020) recently argued that Belinurus König, 1820 is valid and has priority, a position then followed by Lamsdell (2020), prompting a reinvestigation of the taxonomic history of the genus. Upon review, it is clear that neither of the previously recognized authorities for Belinurus are accurate and that the two candidate type species for each genus are, in fact, synonyms. Given the convoluted and at times almost illogical history of the competing names, along with the most recent controversy as to which has priority, we present a complete history of the treatment of the genus to resolve the issue.

Ecological correlates of ghost lineages in ruminants

Paleobiology ◽

10.1017/s0094837300000427 ◽

2012 ◽

Vol 38 (1) ◽

pp. 101-111 ◽

Cited By ~ 2

Author(s):

Juan L. Cantalapiedra ◽

Manuel Hernández Fernández ◽

Gema M. Alcalde ◽

Beatriz Azanza ◽

Daniel DeMiguel ◽

...

Keyword(s):

Fossil Record ◽

Generalized Estimating Equations ◽

Evolutionary History ◽

Phylogenetic Systematics ◽

Temporal Factors ◽

Preservation Potential ◽

History Of ◽

First Time ◽

Pearson Correlations ◽

Bone Remains

Integration between phylogenetic systematics and paleontological data has proved to be an effective method for identifying periods that lack fossil evidence in the evolutionary history of clades. In this study we aim to analyze whether there is any correlation between various ecomorphological variables and the duration of these underrepresented portions of lineages, which we call ghost lineages for simplicity, in ruminants. Analyses within phylogenetic (Generalized Estimating Equations) and non-phylogenetic (ANOVAs and Pearson correlations) frameworks were performed on the whole phylogeny of this suborder of Cetartiodactyla (Mammalia). This is the first time ghost lineages are focused in this way. To test the robustness of our data, we compared the magnitude of ghost lineages among different continents and among phylogenies pruned at different ages (4, 8, 12, 16, and 20 Ma). Differences in mean ghost lineage were not significantly related to either geographic or temporal factors. Our results indicate that the proportion of the known fossil record in ruminants appears to be influenced by the preservation potential of the bone remains in different environments. Furthermore, large geographical ranges of species increase the likelihood of preservation.

The Mesozoic Biogeographic History of Gondwanan Terrestrial Vertebrates: Insights from Madagascar's Fossil Record

Annual Review of Earth and Planetary Sciences ◽

10.1146/annurev-earth-053018-060051 ◽

2019 ◽

Vol 47 (1) ◽

pp. 519-553 ◽

Cited By ~ 11

Author(s):

David W. Krause ◽

Joseph J.W. Sertich ◽

Patrick M. O'Connor ◽

Kristina Curry Rogers ◽

Raymond R. Rogers

Keyword(s):

Late Cretaceous ◽

Fossil Record ◽

Late Jurassic ◽

Indian Subcontinent ◽

Terrestrial Vertebrates ◽

Faunal Assemblages ◽

Theropod Dinosaurs ◽

Biogeographic History ◽

History Of ◽

The Caribbean

The Mesozoic plate tectonic and paleogeographic history of Gondwana had a profound effect on the distribution of terrestrial vertebrates. As the supercontinent fragmented into a series of large landmasses (South America, Africa-Arabia, Antarctica, Australia, New Zealand, the Indian subcontinent, and Madagascar), particularly during the Late Jurassic and Cretaceous, its terrestrial vertebrates became progressively isolated, evolving into unique faunal assemblages. We focus on four clades that, during the Mesozoic, had relatively low ability for dispersal across oceanic barriers—crocodyliforms, sauropod dinosaurs, nonavian theropod dinosaurs, and mammals. Their distributions reveal patterns that are critically important in evaluating various biogeographic hypotheses, several of which have been informed by recent discoveries from the Late Cretaceous of Madagascar. We also examine the effects of lingering, intermittent connections, or reconnections, of Gondwanan landmasses with Laurasia (through the Caribbean, Mediterranean, and Himalayan regions) on the distributions of different clades. ▪ This article reviews the biogeographic history of terrestrial vertebrates from the Mesozoic of the southern supercontinent Gondwana. ▪ Relatively large, terrestrial animals—including crocodyliforms, sauropod and nonavian theropod dinosaurs, and mammals—are the focus of this review. ▪ Most patterns related to vicariance occurred during the Late Jurassic and Cretaceous, the intervals of most active Gondwanan fragmentation. ▪ Recent discoveries of vertebrates from the Late Cretaceous of Madagascar have played a key role in formulating and testing various biogeographic hypotheses.

A new testudinoid turtle from the middle to late Eocene of Vietnam

PeerJ ◽

10.7717/peerj.6280 ◽

2019 ◽

Vol 7 ◽

pp. e6280 ◽

Cited By ~ 1

Author(s):

Rafaella C. Garbin ◽

Madelaine Böhme ◽

Walter G. Joyce

Keyword(s):

Late Eocene ◽

Total Evidence ◽

New Taxon ◽

Phylogenetic Placement ◽

The Matrix ◽

History Of ◽

New Material ◽

Evidence Analysis ◽

Random Variability ◽

Background Testudinoidea is a major clade of turtles that has colonized different ecological environments across the globe throughout the Tertiary. Aquatic testudinoids have a particularly rich fossil record in the Tertiary of the northern hemisphere, but little is known about the evolutionary history of the group, as the phylogenetic relationships of most fossils have not been established with confidence, in part due to high levels of homoplasy and polymorphism. Methods We here focus on describing a sample of 30 testudinoid shells, belonging to a single population that was collected from lake sediments from the middle to late Eocene (35–39 Ma) Na Duong Formation in Vietnam. The phylogenetic placement of this new material is investigated by integrating it and 11 other species of putative geoemydids from the Eocene and Oligocene to a recently published matrix of geoemydid turtles, that embraces the use of polymorphic characters, and then running a total-evidence analysis. Results The new material is highly polymorphic, but can be inferred with confidence to be a new taxon, Banhxeochelys trani gen. et sp. nov. It shares morphological similarities with other southeastern Asian testudinoids, Isometremys lacuna and Guangdongemys pingi, but is placed phylogenetically at the base of Pan-Testuguria when fossils are included in the analysis, or as a stem geoemydid when other fossils are deactivated from the matrix. The vast majority of other putative fossil geoemydids are placed at the base of Pan-Testuguria as well. Discussion The phylogenetic placement of fossil testudinoids used in the analysis is discussed individually and each species compared to Banhxeochelys trani gen. et sp. nov. The high levels of polymorphism observed in the new taxon is discussed in terms of ontogenetic and random variability. This is the first time that a large sample of fossil testudinoids has its morphological variation described in detail.

First report ofOniscidiaMörch, 1852 (Neogastropoda, Harpidae) in the northeast Pacific fossil record and paleobiogeographic review of the genus

10.1017/jpa.2018.13 ◽

2018 ◽

Vol 92 (5) ◽

pp. 794-803

Author(s):

Richard L. Squires

Keyword(s):

Fossil Record ◽

Middle Eocene ◽

Turbidity Currents ◽

Northeast Pacific ◽

Early Paleocene ◽

History Of ◽

Taxonomic Confusion ◽

The Caribbean ◽

First Time ◽

The Western Pacific

AbstractThe harpid neogastropod genusOniscidiaMörch, 1852, which has not been recognized before in the northeast Pacific fossil record, is represented there by rare specimens ofOniscidia plectata(Waring, 1917) n. comb., of late early Paleocene age, in a region extending from southern California, USA to Baja California, Mexico. This species is the earliest unequivocal record ofOniscidiaand its only known Paleocene record. It apparently lived in silty, inner- to middle-shelf depths, which were inherently cooler than adjacent shallower marine depths. Its habitat was subject to the influx of shallow-marine shells, especially turritellas, contained in turbidity currents emanating from nearshore depths.The global paleogeography ofOniscidia, which is presented here for the first time, has been overlooked previously because this genus has a long and complicated history of taxonomic confusion with the harpid genusMorumRöding, 1798.Oniscidiaquestionably originated during the Late Cretaceous (Campanian) in southern India and apparently dispersed westward through the Tethys Seaway into the New World. Paleocene and early Eocene occurrences of this genus are rare, and middle Eocene occurrences are uncommon. During the cool times of the Oligocene and into the early Miocene, it was most widespread. Its range became restricted during the middle Miocene and continued to be so during the Pliocene, Pleistocene, and modern day, with occurrences only in the Caribbean Sea region, Florida, and the western Pacific. Its distribution through warm and cool times was most likely controlled by its habitat preference for relatively deep cool waters.

Darwin's two competing phylogenetic trees: marsupials as ancestors or sister taxa?

Archives of Natural History ◽

10.3366/anh.2012.0091 ◽

2012 ◽

Vol 39 (2) ◽

pp. 217-233 ◽

Cited By ~ 4

Author(s):

J. David Archibald

Keyword(s):

Fossil Record ◽

Evolutionary Biology ◽

Phylogenetic Trees ◽

Charles Darwin ◽

The Other ◽

Charles Lyell ◽

Single Origin ◽

Molecular Studies ◽

Richard Owen ◽

Studies of the origin and diversification of major groups of plants and animals are contentious topics in current evolutionary biology. This includes the study of the timing and relationships of the two major clades of extant mammals – marsupials and placentals. Molecular studies concerned with marsupial and placental origin and diversification can be at odds with the fossil record. Such studies are, however, not a recent phenomenon. Over 150 years ago Charles Darwin weighed two alternative views on the origin of marsupials and placentals. Less than a year after the publication of On the origin of species, Darwin outlined these in a letter to Charles Lyell dated 23 September 1860. The letter concluded with two competing phylogenetic diagrams. One showed marsupials as ancestral to both living marsupials and placentals, whereas the other showed a non-marsupial, non-placental as being ancestral to both living marsupials and placentals. These two diagrams are published here for the first time. These are the only such competing phylogenetic diagrams that Darwin is known to have produced. In addition to examining the question of mammalian origins in this letter and in other manuscript notes discussed here, Darwin confronted the broader issue as to whether major groups of animals had a single origin (monophyly) or were the result of “continuous creation” as advocated for some groups by Richard Owen. Charles Lyell had held similar views to those of Owen, but it is clear from correspondence with Darwin that he was beginning to accept the idea of monophyly of major groups.

Adam Zalužanský’s “De sexu plantarum” (1592): an early pioneering chapter on plant sexuality

Archives of Natural History ◽

10.3366/anh.2013.0171 ◽

2013 ◽

Vol 40 (2) ◽

pp. 244-256 ◽

Cited By ~ 4

Author(s):

Holger Funk

Keyword(s):

Nineteenth Century ◽

English Translation ◽

History Of Botany ◽

Main Work ◽

Botanical History ◽

History Of ◽

The University ◽

In the history of botany, Adam Zalužanský (d. 1613), a Bohemian physician, apothecary, botanist and professor at the University of Prague, is a little-known personality. Linnaeus's first biographers, for example, only knew Zalužanský from hearsay and suspected he was a native of Poland. This ignorance still pervades botanical history. Zalužanský is mentioned only peripherally or not at all. As late as the nineteenth century, a researcher would be unaware that Zalužanský’s main work Methodi herbariae libri tres actually existed in two editions from two different publishers (1592, Prague; 1604, Frankfurt). This paper introduces the life and work of Zalužanský. Special attention is paid to the chapter “De sexu plantarum” of Zalužanský’s Methodus, in which, more than one hundred years before the well-known De sexu plantarum epistola of R. J. Camerarius, the sexuality of plants is suggested. Additionally, for the first time, an English translation of Zalužanský’s chapter on plant sexuality is provided.