scholarly journals Therian mammals experience an ecomorphological radiation during the Late Cretaceous and selective extinction at the K–Pg boundary

2016 ◽  
Vol 283 (1832) ◽  
pp. 20160256 ◽  
Author(s):  
David M. Grossnickle ◽  
Elis Newham
Keyword(s):  
Late Cretaceous ◽  
Taxonomic Diversity ◽  
Flowering Plants ◽  
Generic Level ◽  
Morphological Disparity ◽  
Morphological Diversification ◽  
Diversity Patterns ◽  
Morphometric Analyses ◽  
Extinction Event ◽  
Selective Extinction

It is often postulated that mammalian diversity was suppressed during the Mesozoic Era and increased rapidly after the Cretaceous–Palaeogene (K–Pg) extinction event. We test this hypothesis by examining macroevolutionary patterns in early therian mammals, the group that gave rise to modern placentals and marsupials. We assess morphological disparity and dietary trends using morphometric analyses of lower molars, and we evaluate generic level taxonomic diversity patterns using techniques that account for sampling biases. In contrast with the suppression hypothesis, our results suggest that an ecomorphological diversification of therians began 10–20 Myr prior to the K–Pg extinction event, led by disparate metatherians and Eurasian faunas. This diversification is concurrent with ecomorphological radiations of multituberculate mammals and flowering plants, suggesting that mammals as a whole benefitted from the ecological rise of angiosperms. In further contrast with the suppression hypothesis, therian disparity decreased immediately after the K–Pg boundary, probably due to selective extinction against ecological specialists and metatherians. However, taxonomic diversity trends appear to have been decoupled from disparity patterns, remaining low in the Cretaceous and substantially increasing immediately after the K–Pg extinction event. The conflicting diversity and disparity patterns suggest that earliest Palaeocene extinction survivors, especially eutherian dietary generalists, underwent rapid taxonomic diversification without considerable morphological diversification.

scholarly journals Diversity, diets and disparity: determining the effect of the terminal Cretaceous extinction on insect evolution

1992 ◽  
Vol 6 ◽  
pp. 174-174 ◽  
Author(s):  
Conrad C. Labandeira
Keyword(s):  
Data Base ◽  
Fossil Record ◽  
Taxonomic Diversity ◽  
Flowering Plants ◽  
Flowering Plant ◽  
Plant Interactions ◽  
Insect Evolution ◽  
Leaf Mining ◽  
Extinction Event ◽  
Wood Boring

A considerable amount of research has been devoted toward evaluating the impact of the Cretaceous/Tertiary extinction on terrestrial life. This research has focused primarily on terrestrial vertebrates (primarily dinosaurs), marine invertebrates (notably molluscs and foraminifera), and to a lesser extent, terrestrial vascular plants. Terrestrial arthropods, especially insects, have seldomly been investigated, principally because of an alleged depauperate fossil record. Nevertheless, within the past two decades, some of the most productive and taxonomically diverse insect faunas have originated from Cretaceous amber- and compression-fossil deposits from every continent. Whereas it was once thought that the Cretaceous represented an unknown void in the understanding of insect evolution, now it appears that many extant lineages are traceable to Cretaceous precursors.Three approaches are available for determining the extent of the effect of the terminal Cretaceous extinction event on insects. Assessed for the interval from the Early Cretaceous to the Early Paleogene, these approaches are: (1) establishing the secular pattern of familial- and generic-based taxonomic diversity (macroevolution); (2) recognizing the persistence or eradication of specific insect/vascular plant interactions, such as leaf-mining, wood-boring and pollination (behavior); and (3) establishing temporal trends in the range of mouthpart design, as an indicator of faunal disparity or structural diversity (morphology). These three operationally separate but complimentary approaches allow the advantage of using distinct data bases to bear on a common question. The body-fossil record of insects provides primary data for the taxonomic expansion, steady-state, or contraction of insect faunas. The trace-fossil record of those insect interactions that are coevolved with plant hosts reveals the temporal continuity of highly stereotyped and taxonomically obligate behaviors. Both of these are contrasted to an assessment of insectan structural disparity, herein determined from a robust data base of 30 modern insect mouthpart classes that are traced back in geologic time.A preliminary analysis of each of these three approaches indicates broad agreement–namely that insects were not dramatically affected by the terminal Cretaceous extinction event. First, insects experienced only a modest decline in diversity, about 9 percent at the family level. (The generic level is not yet analyzed.) Second, although the data base is limited, there is no indication of the extinction of major leaf-mining, wood-boring, pollinating or other plant-specific behaviors at the end of the Cretaceous. In fact, leaf-mine morphologies for three lepidopteran families with Cretaceous occurrences are apparently indistinguishable from their modern descendants. Last, of the 30 mouthpart classes occurring during the Paleogene, 28 are represented during the Cretaceous. These data provide strong evidence for a largely uninterrupted continuum of insect faunas across the Cretaceous/Tertiary boundary as measured by taxonomic diversity, coevolved behavior, and structural disparity.Because of abundant and often intimate associations between insects and flowering plants, these results are consistent with a gradual and not catastrophic change in terrestrial floras across the Cretaceous/Tertiary boundary. Acceptance of a catastrophic extinction of flowering plants during the terminal Cretaceous would necessitate an unprecedented level of host-switching by coevolved insects on contemporaneous plants. This is unlikely, based on evidence from the prolific literature on modern insect/plant interactions. These studies indicate the ubiquity of obligate insect specificity for various secondary chemicals on many flowering plant species.

scholarly journals Decoupling of morphological disparity and taxonomic diversity during the end-Permian mass extinction

Paleobiology ◽  
2021 ◽  
pp. 1-16
Author(s):  
Junyu Wan ◽  
William J. Foster ◽  
Li Tian ◽  
Thomas L. Stubbs ◽  
Michael J. Benton ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Microbial Mats ◽  
Benthic Communities ◽  
Ecological Impact ◽  
Taxonomic Diversity ◽  
Morphological Disparity ◽  
Extinction Event ◽  
Permian Extinction ◽  
Permian Mass Extinction ◽  
Marine Platform

Abstract An increasing number of unexpectedly diverse benthic communities are being reported from microbially precipitated carbonate facies in shallow-marine platform settings after the end-Permian mass extinction. Ostracoda, which was one of the most diverse and abundant metazoan groups during this interval, recorded its greatest diversity and abundance associated with these facies. Previous studies, however, focused mainly on taxonomic diversity and, therefore, left room for discussion of paleoecological significance. Here, we apply a morphometric method (semilandmarks) to investigate morphological variance through time to better understand the ecological consequences of the end-Permian mass extinction and to examine the hypothesis that microbial mats played a key role in ostracod survival. Our results show that taxonomic diversity and morphological disparity were decoupled during the end-Permian extinction and that morphological disparity declined rapidly at the onset of the end-Permian extinction, even though the high diversity of ostracods initially survived in some places. The decoupled changes in taxonomic diversity and morphological disparity suggest that the latter is a more robust proxy for understanding the ecological impact of the extinction event, and the low morphological disparity of ostracod faunas is a consequence of sustained environmental stress or a delayed post-Permian radiation. Furthermore, the similar morphological disparity of ostracods between microbialite and non-microbialite facies indicates that microbial mats most likely represent a taphonomic window rather than a biological refuge during the end-Permian extinction interval.

scholarly journals Mammal disparity decreases during the Cretaceous angiosperm radiation

2013 ◽  
Vol 280 (1771) ◽  
pp. 20132110 ◽  
Author(s):  
David M. Grossnickle ◽  
P. David Polly
Keyword(s):  
Functional Morphology ◽  
Late Cretaceous ◽  
Morphometric Analysis ◽  
Small Body ◽  
Flowering Plants ◽  
Morphological Disparity ◽  
The Past ◽  
Body Sizes ◽  
Mammal Evolution ◽  
Functional Shift

Fossil discoveries over the past 30 years have radically transformed traditional views of Mesozoic mammal evolution. In addition, recent research provides a more detailed account of the Cretaceous diversification of flowering plants. Here, we examine patterns of morphological disparity and functional morphology associated with diet in early mammals. Two analyses were performed: (i) an examination of diversity based on functional dental type rather than higher-level taxonomy, and (ii) a morphometric analysis of jaws, which made use of modern analogues, to assess changes in mammalian morphological and dietary disparity. Results demonstrate a decline in diversity of molar types during the mid-Cretaceous as abundances of triconodonts, symmetrodonts, docodonts and eupantotherians diminished. Multituberculates experience a turnover in functional molar types during the mid-Cretaceous and a shift towards plant-dominated diets during the late Late Cretaceous. Although therians undergo a taxonomic expansion coinciding with the angiosperm radiation, they display small body sizes and a low level of morphological disparity, suggesting an evolutionary shift favouring small insectivores. It is concluded that during the mid-Cretaceous, the period of rapid angiosperm radiation, mammals experienced both a decrease in morphological disparity and a functional shift in dietary morphology that were probably related to changing ecosystems.

scholarly journals A new small deinonychosaur (Dinosauria: Theropoda) from the Late Cretaceous of Patagônia, Argentina

2011 ◽  
Vol 83 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Juan D. Porfiri ◽  
Jorge O. Calvo ◽  
Domenica dos Santos
Keyword(s):  
Late Cretaceous ◽  
Taxonomic Diversity ◽  
South American ◽  
New Material ◽  
New Evidence

Here we report on a new small deinonychosaurian theropod, Pamparaptor micros gen. et sp. nov., from the Late Cretaceous of Patagônia, Argentina. Pamparaptor micros exhibits a pedal structure previously unknown among South Américan deinonychosaurians. The new material provides new evidence about the morphology and taxonomic diversity of Patagônian deinonychosaurs. Pamparaptor is the smaller non-avialae Patagônian deinonychosaur, probably with about 0.50-0.70 meters, long. The pedal construction resembles, that of Troodontid or basal Dromaeosaurids. Nevertheless, up to now, we considered Pamparaptor a peculiar Patagônian Dromaeosaurid with troodontid-like pes.

scholarly journals Late Cretaceous non-marine turtles of Asia: a review of taxonomic diversity and paleobiogeography

2015 ◽  
Author(s):  
Igor Danilov ◽  
Ekaterina Obraztsova ◽  
Vladimir Sukhanov
Keyword(s):  
Late Cretaceous ◽  
Environmental Conditions ◽  
Geographical Area ◽  
Temporal Distribution ◽  
Taxonomic Diversity ◽  
Coastal Areas ◽  
Marine Turtle ◽  
Marine Turtles ◽  
Middle Asia ◽  
Different Ages

Background. This report reviews data on taxonomic diversity and paleobiogeography of Late Cretaceous (K2) non-marine turtles of Asia accumulated since latest reviews in 2000s. K2 non-marine turtles of Asia are known from four main geographical areas: Middle Asia-Kazakhstan (MAK), Mongolia (MO), China (CH) and Japan (JA). Methods. We critically reviewed composition of non-marine turtle assemblages of the K2 for each of the mentioned geographical area to make estimates of taxonomic diversity for different ages of the K2. Based on these data we analyzed temporal distribution of taxa of non-marine turtles and change in taxonomic diversity of turtle assemblages. Results. K2 turtles of MAK are represented by eight suprageneric taxa – Adocidae (Ad), Carettochelyidae (Ca), Lindholmemydidae (Li), Macrobaenidae (Ma), Nanhsiungchelyidae (Na), Trionychidae (Tr), Eucryptodira indet. (Eu), and Testudines indet. (Te), of which Ad, Li, Ma and Tr are known from the Cenomanian(CE) – early Campanian(CA), whereas other taxa only from the CE-early Turonian(TU). Taxonomic diversity changes from 10–12 species and genera, 6–8 suprageneric taxa in the CE to 7 species and genera, 4 families in the late TU early CA. K2 turtles of MO are represented by seven suprageneric taxa – Ad, Ca, Li, Ma, Meiolaniformes (Me), Na, and Tr, of which Li, Na and Tr are known from the CE-Maastrichtian(MA), Ad, Ca, and Ma, from the CE-Santonian(SA), and Me, only from the MA. Taxonomic diversity changes from 12 species, 10 genera, 6 families in the CE – SA, 8–9 species, 7–9 genera, 3 families in the CA, and 9 species, 7–8 genera, and 4 suprageneric taxa in the MA. K2 turtles of CH are represented by three suprageneric taxa (Li, Na, and Tr), but their precise temporal distribution is poorly known. Taxonomic diversity in the K2 is 12 species, 11–12 genera, and 3 families. K2 turtles of JA are represented by six suprageneric taxa (Ad, Ca, Na, Tr, Eu, and Te), of which Na are known from the CE-SA, Tr from the Coniacian(CO)-CA, and other taxa from the CO-SA. Taxonomic diversity changes from 1 species, genus, and family in the CE-TU to 7 species and genera, and 5–6 suprageneric taxa in the CO-SA. Discussion. In MAK, most significant transformation of turtle assemblages occurred in the CE-TU, whereas transformation in the SA-CA was less significant. On the contrary, in MO, most significant transformation occurred in the SA-CA, and less significant in the CA-MA.The patterns of transformation of the K2 turtle assemblages of CH and JA are not clear. The differences in the patterns of diversity and transformations of the K2 turtle assemblages in different geographical areas of Asia may be explained by different environmental conditions in these areas at that time and influence of such factors as transgressions in coastal areas (MAK and JA) and cooling and aridizations in inland areas (MO and CH).

scholarly journals Impact of transition to a subterranean lifestyle on morphological disparity and integration in talpid moles (Mammalia, Talpidae)

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Gabriele Sansalone ◽  
Paolo Colangelo ◽  
Anna Loy ◽  
Pasquale Raia ◽  
Stephen Wroe ◽  
...  
Keyword(s):  
Evolutionary Biology ◽  
Morphological Variability ◽  
Phenotypic Integration ◽  
Phenotypic Traits ◽  
Phenotypic Evolution ◽  
Morphological Disparity ◽  
Morphological Diversification ◽  
Phylogenetic Conservatism ◽  
Selective Forces ◽  
Subterranean Species

Abstract Background Understanding the mechanisms promoting or constraining morphological diversification within clades is a central topic in evolutionary biology. Ecological transitions are of particular interest because of their influence upon the selective forces and factors involved in phenotypic evolution. Here we focused on the humerus and mandibles of talpid moles to test whether the transition to the subterranean lifestyle impacted morphological disparity and phenotypic traits covariation between these two structures. Results Our results indicate non-subterranean species occupy a significantly larger portion of the talpid moles morphospace. However, there is no difference between subterranean and non-subterranean moles in terms of the strength and direction of phenotypic integration. Conclusions Our study shows that the transition to a subterranean lifestyle significantly reduced morphological variability in talpid moles. However, this reduced disparity was not accompanied by changes in the pattern of traits covariation between the humerus and the mandible, suggesting the presence of strong phylogenetic conservatism within this pattern.

Evolution and Expansion of Flowering Plants

2000 ◽  
Vol 6 ◽  
pp. 209-232 ◽  
Author(s):  
Scott L. Wing
Keyword(s):  
Large Scale ◽  
Terrestrial Ecosystems ◽  
Taxonomic Diversity ◽  
Climatic Conditions ◽  
Flowering Plants ◽  
Terrestrial Vegetation ◽  
Earth History ◽  
Very High ◽  
High Diversity ◽  
Environmental Disruption

Flowering plants are a classic example of a group arising late in Earth history and yet achieving very high diversity, abundance, and ecological and morphological variety in a great array of environments and climatic conditions on all continents. Thus, the success of flowering plants raises basic questions about how new lineages become inserted into existing terrestrial ecosystems. To what degree did flowering plants replace older lineages competitively, and to what extent did their expansion depend on large-scale environmental disruption or extinction of older groups? Is the higher taxonomic diversity of flowering plants a consequence of higher rates of speciation, lower rates of extinction, or both? Have flowering plants expanded the total area and range of habitats occupied by terrestrial vegetation? What were the effects of the diversification and spread of flowering plants on the structure of habitats and the types of resources available to terrestrial heterotrophs?

scholarly journals Permian phytogeography and climate

1992 ◽  
Vol 6 ◽  
pp. 329-329
Author(s):  
Alfred M. Ziegler ◽  
Eric D. Gyllenhaal
Keyword(s):  
General Circulation ◽  
General Scheme ◽  
Geographic Distance ◽  
Circulation Model ◽  
Taxonomic Diversity ◽  
Critical Groups ◽  
Multivariate Techniques ◽  
Generic Level ◽  
Temperature And Precipitation ◽  
Geographic Separation

A greater number of floral provinces have been defined for the Permian than for any other Phanerozoic period, and this is presumably the reflection of a well differentiated set of climate zones. These floras have been assigned to an idealized set of ten “biomes” as defined on the basis of the equator-to-pole spectrum of present day climates (Ziegler, 1990). The biomes reflect temperature and precipitation, and in particular the way in which these parameters change through the annual cycle. The purpose of the present paper is (1) to expand the taxonomic database of Permian floras and climatically sensitive sediments, (2) to use ordination analyses and other multivariate techniques to relate taxonomic data to climate, geographic distance and other factors that controlled the global distribution of plants, and (3) to relate these results to the recognition of biomes during the Permian.This approach reveals that the phytogeographic provinces, as recognized by paleobotanists, are objectively valid entities, but significant gradations can be detected, supporting the idea that the floras were controlled by climate rather than by geographic separation. In fact, there are no examples in the Permian world of strictly geographic barriers, which is not surprising in view of the fact that the continents were basically together through this time.Biomes are defined by climatic parameters, but the taxonomic characteristics of biomes have evolved with time. The Permian floral provinces can be related to precipitation balance by their associations with such climatically sensitive sediments as coals, paleosols and evaporites, and this is critical for assigning each to an appropriate biome. At least at the generic level, taxonomic lists have significant limitations for identification of biomes in the geologic past. In particular, northern and southern hemisphere temperate biomes evolved radically different floras by the Permian. Ecomorphic characters and taxonomic diversity within critical groups may provide a more general scheme for phytologic recognition of biomes through geologic time.Finally, detailed comparisons will be made to General Circulation Model and Energy Balance studies on the Permian. The numerical studies seem to overemphasize the seasonal extremes of temperature in the middle to high latitudes.

scholarly journals Patterns of morphological diversification in giant Berberomeloe blister beetles (Coleoptera: Meloidae) reveal an unexpected taxonomic diversity concordant with mtDNA phylogenetic structure

2020 ◽  
Vol 189 (4) ◽  
pp. 1249-1312 ◽  
Author(s):  
Alberto Sánchez-Vialas ◽  
Mario García-París ◽  
José L Ruiz ◽  
Ernesto Recuero
Keyword(s):  
New Species ◽  
Genetic Variability ◽  
Phenotypic Variability ◽  
Morphological Diversity ◽  
Taxonomic Diversity ◽  
Molecular Data ◽  
Species Boundaries ◽  
Congeneric Species ◽  
Phylogenetic Structure ◽  
Morphological Diversification

Abstract Delimiting species boundaries is a complex challenge usually hindered by overlooked morphological diversification or misinterpretation of geographically structured phenotypic variability. Independent molecular data are extremely useful to characterize and understand such morphological diversity. Morphological and molecular variability of the non-phoretic and apterous, widely distributed, giant blister beetles of the genus Berberomeloe, were investigated within and between lineages across most of the distributional range of the genus. We used two mtDNA gene fragments to characterize genetic variability and to produce a time-calibrated phylogeny of the genus. Our results reveal several mitochondrial lineages, allopatrically, parapatrically and sympatrically distributed. Most clades are not distinguishable between each other based on morphometrics. However, no morphometric overlap is observed between two closely related clades, one of them occurring in sympatry with a distantly congeneric species (B. insignis), suggesting that sympatry could trigger morphological diversification. Although most species share a morphometric space, they can be morphologically identified by a combination of easily observed characteristic qualitative features. Based on the concordance between mtDNA clades and morphological units, we describe six new species of Berberomeloe (B. castuo sp. nov., B. comunero sp. nov., B. indalo sp. nov, B. yebli sp. nov., B. payoyo sp. nov. and B. tenebrosus sp. nov.), revalidate two taxa (B. maculifrons comb. nov. and B. laevigatus comb. nov.) and redefine B. majalis.

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