Holotypes in the taxonomy of planktonic foraminiferal morphospecies

Scott, G. H.

doi:10.1016/j.marmicro.2010.11.001

Cited by 17 publications

(13 citation statements)

References 19 publications

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“…Heavy reliance on holotypes and typological taxonomy to exemplify a morphospecies' morphology may lead to loss of information about population variation (Emiliani 1969;Scott 2011). The combined effects of typological taxonomy and gradual morphological intergradation between morphospecies inherently lead to artificial subdivision into 'species' (e.g.…”

Section: Typological and Population-based Taxonomic Principlesmentioning

confidence: 99%

“…The combined effects of typological taxonomy and gradual morphological intergradation between morphospecies inherently lead to artificial subdivision into 'species' (e.g. see Fordham 1986;Pearson 1992Pearson , 1993Pearson , 1996Pearson , 1998Scott 2011). Although finer taxonomic splitting may better describe the morphological variation within a given lineage, and certainly facilitate greater biostratigraphical resolution, it does not necessarily convey any evolutionary meaning regarding speciation or extinction (Fordham 1986;Pearson 1992Pearson , 1998Scott 2011).…”

Section: Typological and Population-based Taxonomic Principlesmentioning

confidence: 99%

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Systematic taxonomy of theTrilobatus sacculiferplexus and descendantGlobigerinoidesella fistulosa(planktonic foraminifera)

Poole

Wade

2019

Journal of Systematic Palaeontology

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The extant morphospecies of the Trilobatus sacculifer plexus (T. sacculifer, T. quadrilobatus, T. immaturus and T. trilobus) have widespread biogeographical distributions and long stratigraphical ranges, and are thus routinely utilized in palaeoceanographical studies. The descendant morphospecies Globigerinoidesella fistulosa is comparatively shortranging (Pliocene-Pleistocene) and an important biostratigraphical marker. However, taxonomic concepts of these morphospecies are inconsistently applied between workers, leading to loss of information and incomparable datasets. We present a taxonomic appraisal of each morphospecies, including detailed taxonomic histories and refinement of their morphological concepts, using a combined population-based and typological approach. Morphometric data and scanning electron microscopy are used to illustrate morphological intergradation in the Trilobatus sacculifer plexus. The distinctive morphology of Globigerinoidesella fistulosa is shown to develop from T. sacculifer (as previously documented), but also from the other morphospecies in the plexus, providing the first fossil evidence demonstrating that the four morphospecies of the T. sacculifer plexus are the same species. Our new analyses support culturing and molecular genetic evidence from extant specimens that suggests the four T. sacculifer plexus morphospecies are the same biological species. However, we advocate using the four morphospecies concepts (T. sacculifer, T. quadrilobatus, T. immaturus and T. trilobus) and G. fistulosa, here refined, to increase their palaeoecological and biostratigraphical value.

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Section: Typological and Population-based Taxonomic Principlesmentioning

confidence: 99%

Section: Typological and Population-based Taxonomic Principlesmentioning

confidence: 99%

Systematic taxonomy of theTrilobatus sacculiferplexus and descendantGlobigerinoidesella fistulosa(planktonic foraminifera)

Poole

Wade

2019

Journal of Systematic Palaeontology

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“…First, Foraminifera specimens are generally assigned to morphospecies based on their similarity to designated holotypes (47). Whereas the holotype concept is inherently static and typological, a population is a dynamic entity composed of individuals of varying morphology (37).…”

Section: Evaluating Assumptionsmentioning

confidence: 99%

Assessing the role of cladogenesis in macroevolution by integrating fossil and molecular evidence

Strotz

Allen

2013

Proc. Natl. Acad. Sci. U.S.A.

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Assessing the extent to which population subdivision during cladogenesis is necessary for long-term phenotypic evolution is of fundamental importance in a broad range of biological disciplines. Differentiating cladogenesis from anagenesis, defined as evolution within a species, has generally been hampered by dating precision, insufficient fossil data, and difficulties in establishing a direct link between morphological changes detectable in the fossil record and biological species. Here we quantify the relative frequencies of cladogenesis and anagenesis for macroperforate planktic Foraminifera, which arguably have the most complete fossil record currently available, to address this question. Analyzing this record in light of molecular evidence, while taking into account the precision of fossil dating techniques, we estimate that the fraction of speciation events attributable to anagenesis is <19% during the Cenozoic era (last 65 Myr) and <10% during the Neogene period (last 23 Myr). Our central conclusion-that cladogenesis is the predominant mode by which new planktic Foraminifera taxa become established at macroevolutionary time scales-differs markedly from the conclusion reached in a recent study based solely on fossil data. These disparate findings demonstrate that interpretations of macroevolutionary dynamics in the fossil record can be fundamentally altered in light of genetic evidence. anagenesis, which occurs within a species, and cladogenesis, which occurs during speciation and results in the subdivision of a species into two reproductively isolated, independently evolving taxa (1, 2). Distinguishing between these modes is essential to determining the role of population subdivision in evolutionary dynamics (3,4). This topic has received considerable attention in paleontology (1, 2), perhaps because the fossil record provides the only direct record of long-term morphological change (5), but its importance extends to other biological disciplines. For example, in population genetics, models only predict that phenotypic change is contingent upon or associated with the evolution of reproductive isolation under specific circumstances (3). Thus, a primary role for cladogenesis may highlight the importance of particular speciation modes (2), metapopulations dynamics (6), or adaptive peaks in fitness landscapes (7,8). In community ecology, both evolutionary modes may influence biodiversity, but the mechanisms differ: only cladogenesis results in an increase in diversity (9-11), but anagenesis may help maintain diversity if it results in niche differences that facilitate species coexistence (12, 13).Remarkably few studies have attempted to quantify the relative frequencies of anagenesis and cladogenesis for entire species assemblages (e.g., refs. 5, 14, 15). Addressing this question is challenging due to insufficient fossil data for most taxa and the difficulties in relating morphological change to genetic divergence and the evolution of reproductive isolation (16). Fossil data can only be used to distinguish anag...

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“…In the past and up to present, typological species concepts of foraminifera prevailed, at least in paleontology. Frequently they originated from the 1950s to 1970s petroleum industry for quick age dating of sediments (McGowran 2005), and thereby grossly neglected the complex variability on inter-and intraspecific level (Scott 2011). In the meantime, the scientific community is becoming aware of this deficiency and currently about 30 different species concepts have been proposed (Mallet 2007;Hohenegger 2014).…”

Section: Introductionmentioning

confidence: 99%

Evolutionary prospection in the Neogene planktic foraminifer Globorotalia menardii and related forms from ODP Hole 925B (Ceara Rise, western tropical Atlantic): evidence for gradual evolution superimposed by long distance dispersal?

Knappertsbusch

2016

Swiss J Palaeontol

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Holotypes in the taxonomy of planktonic foraminiferal morphospecies

Cited by 17 publications

References 19 publications

Systematic taxonomy of theTrilobatus sacculiferplexus and descendantGlobigerinoidesella fistulosa(planktonic foraminifera)

Systematic taxonomy of theTrilobatus sacculiferplexus and descendantGlobigerinoidesella fistulosa(planktonic foraminifera)

Assessing the role of cladogenesis in macroevolution by integrating fossil and molecular evidence

Evolutionary prospection in the Neogene planktic foraminifer Globorotalia menardii and related forms from ODP Hole 925B (Ceara Rise, western tropical Atlantic): evidence for gradual evolution superimposed by long distance dispersal?

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