Enrichment and stability in the Pliocene mammalian fauna of North China

Paleobiology ◽  
1991 ◽  
Vol 17 (3) ◽  
pp. 246-265 ◽  
Author(s):  
Lawrence J. Flynn ◽  
Richard H. Tedford ◽  
Qiu Zhanxiang
Keyword(s):  
North America ◽  
Small Mammals ◽  
Fossil Record ◽  
North China ◽  
Species Level ◽  
Large Mammals ◽  
Mammalian Fauna ◽  
Long Distance ◽  
Late Neogene ◽  
Middle Pliocene

The Late Neogene vertebrate fossil record from Yushe Basin presents multiple, superposed assemblages from a single area, spanning roughly the interval of 6–2 Ma. Both large and small mammals show peak species richness in the middle Pliocene but indicate relative faunal stability throughout the Pliocene. Large mammals show turnover, especially extinction, around 5 and 2.5 Ma. Small mammals indicate change (over half of the species and several genera), as well as turnover at the species level, between 4 and 3.4 Ma. The loosely controlled dating of these events does not disprove hypothetical correlation with events in North America and with global climatic shifts. Elements that lack Yushe antecedents, some being long-distance dispersers, appear throughout the section, but with little effect on the resident assemblage. First records of well-documented immigrants (from North America, Europe, Africa, southern Asia, or high latitudes) generally do not coincide with ecomorph extinctions. Early Pliocene exchange between Asia and North America appears to have been balanced in both directions and involved a small proportion of the fauna. Immigration probably was opportunistic and contributed to faunal enrichment. We interpret the Yushe Pliocene mammalian assemblages as representing a fauna that was stable from ca. 5 to 2.5 Ma and changed mainly by additions and congeneric species substitutions.

scholarly journals On calibrating the completometer for the mammalian fossil record

Paleobiology ◽  
2021 ◽  
pp. 1-11
Author(s):  
Indrė Žliobaitė ◽  
Mikael Fortelius
Keyword(s):  
Species Diversity ◽  
Small Mammals ◽  
Fossil Record ◽  
Mammalian Species ◽  
Taxonomic Diversity ◽  
Primate Species ◽  
Large Mammals ◽  
Fossil Species ◽  
Mammalian Fossil ◽  
Taxonomic Groups

Abstract We know that the fossil record is incomplete. But how incomplete? Here we very coarsely estimate the completeness of the mammalian record in the Miocene, assuming that the duration of a mammalian species is about 1 Myr and the species diversity has stayed constant and is structurally comparable to the taxonomic diversity today. The overall completeness under these assumptions appears to be around 4%, but there are large differences across taxonomic groups. We find that the fossil record of proboscideans and perissodactyls as we know it for the Miocene must be close to complete, while we might know less than 15% of the species of artiodactyl or carnivore fossil species and only about 1% of primate species of the Miocene. The record of small mammals appears much less complete than that of large mammals.

scholarly journals Potential impact of mammal defaunation on the early regeneration of a large-seeded palm in the Brazilian Atlantic Forest

2020 ◽  
Vol 15 (2) ◽  
pp. 177-193
Author(s):  
Ana Y. Y. Meiga ◽  
Alexander V. Christianini
Keyword(s):  
Seed Dispersal ◽  
Atlantic Forest ◽  
Small Mammals ◽  
Animal Species ◽  
Large Mammals ◽  
Long Distance ◽  
Forest Remnant ◽  
Potential Impact ◽  
Fallen Fruit ◽  
Early Regeneration

Defaunation, the decline in animal species and populations, is biased towards large-bodied animals that have unique roles as dispersers of large seeds. However, it is speculated that these roles may still be performed by smaller animals, such as small mammals like rodents and marsupials, that thrive in defaunated sites. We investigated if small mammals can disperse the large-seeded palm Attalea dubia. We performed the study in a well-conserved Atlantic Forest remnant in southeast Brazil that still harbours large mammals, such as tapirs. Focal observations showed that capuchin-monkeys consumed the mesocarp of the fruits and dropped the seeds beneath the plant crown thereafter. Mammals preyed on ca. 1% and removed ca. 15% of the fallen fruit/seed and deposited them up to 15 m away. Amongst them, small mammals (< 1 kg), such as the squirrel Guerlinguetus brasiliensis and non-identified nocturnal Sigmodontinae, as well as the marsupial Philander frenatus performed the bulk of interactions. Dispersal enhances recruitment, but the short distances of seed removal did not match the current spatial distribution of palm seedlings and juveniles. Recaching rates of hoarded seeds were small (2%) and unlikely to increase distances of seed dispersal achieved. Short distances of dispersal would increase plant clumpiness and negative density-dependent effects with time. Although small mammals can provide legitimate dispersal, they cannot fully replace larger frugivorous mammals and maintain long-distance seed dispersal that feeds plant metapopulation dynamics and seed gene flow.

scholarly journals Memoirs of a frequent flier: Phylogenomics reveals 18 long-distance dispersals between North America and South America in the popcorn flowers (Amsinckiinae)

2017 ◽  
Vol 104 (11) ◽  
pp. 1717-1728 ◽  
Author(s):  
C. Matt Guilliams ◽  
Kristen E. Hasenstab-Lehman ◽  
Makenzie E. Mabry ◽  
Michael G. Simpson
Keyword(s):  
North America ◽  
South America ◽  
Long Distance

Taxonomy of Ctenomys (Rodentia: Ctenomyidae) in northwestern Patagonia, Argentina: the occurrence of the “mendocinus” lineage

Mammalia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mauro N. Tammone ◽  
Ulyses F.J. Pardiñas
Keyword(s):  
South America ◽  
Molecular Data ◽  
Species Level ◽  
Subterranean Rodents ◽  
Mammalian Fauna ◽  
Southern South America ◽  
Monte Desert ◽  
Desert Shrub ◽  
Northern Patagonia ◽  
Northern Portion

Abstract Subterranean rodents Ctenomys are iconic representatives of the mammalian fauna from southern South America. Based on molecular data, eight lineages have been identified within the genus, although species-level identifications and relationships are still debated. Until now, the “magellanicus” clade has been the only lineage mentioned from arid, extra-Andean portions of Patagonia. Here, we report the presence of a Ctenomys population from northern Patagonia that is unambiguously associated with the Central Argentinean “mendocinus” lineage. Most of the 160,000 km2 comprising the northern portion of Patagonia – an area consisting primarily of Monte Desert shrub-land – are inhabited by Ctenomys populations of unknown taxonomy.

Anatomical, morphometric, and stratigraphic analyses of theropod biodiversity in the Upper Cretaceous (Campanian) Dinosaur Park Formation

2021 ◽  
pp. 1-15
Author(s):  
Thomas M. Cullen ◽  
Lindsay Zanno ◽  
Derek W. Larson ◽  
Erinn Todd ◽  
Philip J. Currie ◽  
...  
Keyword(s):  
High Resolution ◽  
North America ◽  
Fossil Record ◽  
Upper Cretaceous ◽  
Environmental Changes ◽  
Morphometric Analyses ◽  
Variable Distribution ◽  
Taxic Diversity ◽  
Dinosaur Park Formation ◽  
Broad Scale

The Dinosaur Park Formation (DPF) of Alberta, Canada, has produced one of the most diverse dinosaur faunas, with the record favouring large-bodied taxa, in terms of number and completeness of skeletons. Although small theropods are well documented in the assemblage, taxonomic assessments are frequently based on isolated, fragmentary skeletal elements. Here we reassess DPF theropod biodiversity using morphological comparisons, high-resolution biostratigraphy, and morphometric analyses, with a focus on specimens/taxa originally described from isolated material. In addition to clarifying taxic diversity, we test whether DPF theropods preserve faunal zonation/turnover patterns similar to those previously documented for megaherbivores. Frontal bones referred to a therizinosaur (cf. Erlikosaurus), representing among the only skeletal record of the group from the Campanian–Maastrichtian (83–66 Ma) fossil record of North America, plot most closely to troodontids in morphospace, distinct from non-DPF therizinosaurs, a placement supported by a suite of troodontid anatomical frontal characters. Postcranial material referred to cf. Erlikosaurus in North America is also reviewed and found most similar in morphology to caenagnathids, rather than therizinosaurs. Among troodontids, we document considerable morphospace and biostratigraphic overlap between Stenonychosaurus and the recently described Latenivenatrix, as well as a variable distribution of putatively autapomorphic characters, calling the validity of the latter taxon into question. Biostratigraphically, there are no broad-scale patterns of faunal zonation similar to those previously documented in ornithischians from the DPF, with many theropods ranging throughout much of the formation and overlapping extensively, possibly reflecting a lack of sensitivity to environmental changes, or other cryptic ecological or evolutionary factors.

A review of gall midges (Diptera: Cecidomyiidae) described from Mesozoic deposits

2021 ◽  
Vol 4 (1) ◽  
pp. 001-014
Author(s):  
MATHIAS JASCHHOF
Keyword(s):  
New Zealand ◽  
North America ◽  
Fossil Record ◽  
Morphological Diversity ◽  
Sensu Stricto ◽  
Junior Synonym ◽  
Gall Midges ◽  
Incertae Sedis ◽  
New Tribe

Twenty-four fossil gall midges (Cecidomyiidae) described from 1917–2020 from Mesozoic deposits, mostly ambers, are reviewed. Information from the original publications is used as the basis for reinterpretation, when such is regarded as appropriate here. As a result, the fossil record of cecidomyiids from the Mesozoic comprises representatives of the following subfamilies and tribes, all mycophagous (numbers in parentheses refer to species described): Catotrichinae (1); Micromyinae: Catochini (2), Amediini (1), Campylomyzini (1), Micromyini (2) and Aprionini (1); Winnertziinae: Heteropezini (2), Diallactiini (4) and Winnertziini (1); Porricondylinae: Dicerurini (1). Other Winnertziinae (3) and Micromyinae (5) cannot be classified to tribe because information on critical morphological structures is unavailable; they are thus considered incertae sedis. Members of the Lestremiinae sensu stricto are unrecorded from the Mesozoic, as are any Cecidomyiinae (the only subfamily containing phytophages and predators). Commonly occurring reasons for misinterpretation of amber fossils are the non-recognition of artefacts and the unfamiliarity with group-specific literature regarding prevailing taxonomic concepts and the morphological diversity found in Cecidomyiidae. These causes as well as obvious differences between neontological and paleontological taxonomic practices are discussed. Amediini trib. nov. Jaschhof, 2021 is introduced as a new tribe of the Micromyinae, to absorb the genera Amedia Jaschhof, 1997 (extant, North America, type genus), Amediella Jaschhof, 2003 (extant, New Zealand) and Eltxo Arillo & Nel, 2000 (extinct, Alava amber). A diagnosis of the new tribe is given. Krassiloviolini Fedotova & Perkovsky, 2017 is a new junior synonym of Heteropezini Schiner, 1868. Amediini Plakidas, 2017 and Zarqacecidomyius singularis Kaddumi, 2007 are nomina nuda.

scholarly journals Colouration, chaetotaxy and molecular data provide species-level resolution in a species complex of Dicranocentrus (Collembola : Entomobryidae)

2018 ◽  
Vol 32 (6) ◽  
pp. 1298 ◽  
Author(s):  
Feng Zhang ◽  
Daoyuan Yu ◽  
Mark I. Stevens ◽  
Yinhuan Ding
Keyword(s):  
Species Complex ◽  
Instar Larva ◽  
Molecular Data ◽  
Integrative Taxonomy ◽  
Species Level ◽  
Integrative Approach ◽  
Gene Markers ◽  
Late Neogene ◽  
Taxonomic Approach ◽  
Colour Patterns

Integrative taxonomic approaches are increasingly providing species-level resolution to ‘cryptic’ diversity. In the absence of an integrative taxonomic approach, formal species validation is often lacking because of inadequate morphological diagnoses. Colouration and chaetotaxy are the most commonly used characters in collembolan taxonomy but can cause confusion in species diagnoses because these characters often have large intraspecific variation. Here, we take an integrative approach to the genus Dicranocentrus in China where four species have been previously recognised, but several members of the genus have been morphologically grouped as a species complex based on having paired outer teeth on unguis and seven colour patterns. Molecular delimitations based on distance- and evolutionary models recovered four candidate lineages from three gene markers and revealed that speciation events likely occurred during the late Neogene (4–13million years ago). Comparison of intact dorsal chaetotaxy, whose homologies were erected on the basis of first instar larva, further validated these candidates as formal species: D. gaoligongensis, sp. nov., D. similis, sp. nov., D. pallidus, sp. nov. and D. varicolor, sp. nov., and increase the number of Dicranocentrus species from China to eight. Our study further highlights the importance of adequate taxonomy in linking morphological and molecular characters within integrative taxonomy.

‘Scows, and barges, or other vessels of box model’: Comparative capital investment in the sailing scows of the Great Lakes of North America and in New Zealand

2018 ◽  
Vol 30 (1) ◽  
pp. 89-105
Author(s):  
Jay C. Martin
Keyword(s):  
New Zealand ◽  
North America ◽  
Great Lakes ◽  
Capital Investment ◽  
Open Water ◽  
Long Distance ◽  
American Frontier ◽  
International Context ◽  
The North ◽  
Hull Design

Boxy and with ‘unseaworthy form’, the sailing scow was not the most aesthetically pleasing of watercraft. Yet the durable hull design based upon European predecessors found a new home in North America where it proliferated on the Atlantic, Gulf, Pacific and Great Lakes coasts because of its practicality for largely unimproved waterways. Scows were widely used on the Great Lakes in the nineteenth century, moving beyond shallow waters and gaining a reputation for reliability in long-distance trade. Late in the century, the technology arrived in New Zealand, where it prospered in a niche market that combined open water voyages and shallow river, port, or beach loading and unloading. The Great Lakes scows presented an alternative for entry into ship ownership on the North American frontier. The development of the New Zealand scow confirmed these findings comparatively in an international context during the late nineteenth and early twentieth centuries.

Edges and interactions beyond Europe

2018 ◽  
Author(s):  
Peter S. Wells ◽  
Naoise Mac Sweeney
Keyword(s):  
North America ◽  
Iron Age ◽  
North Atlantic ◽  
Cultural Practices ◽  
Raw Materials ◽  
Long Distance ◽  
The North ◽  
First Millennium ◽  
Temperate Europe ◽  
The North Atlantic

Iron Age Europe, once studied as a relatively closed, coherent continent, is being seen increasingly as a dynamic part of the much larger, interconnected world. Interactions, direct and indirect, with communities in Asia, Africa, and, by the end of the first millennium AD, North America, had significant effects on the peoples of Iron Age Europe. In the Near East and Egypt, and much later in the North Atlantic, the interactions can be linked directly to historically documented peoples and their rulers, while in temperate Europe the evidence is exclusively archaeological until the very end of the prehistoric Iron Age. The evidence attests to often long-distance interactions and their effects in regard to the movement of peoples, and the introduction into Europe of raw materials, crafted objects, styles, motifs, and cultural practices, as well as the ideas that accompanied them.

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