scholarly journals Parallel evolutionary trajectories underlie the origin of giant suspension-feeding whales and bony fishes

2011 ◽  
Vol 279 (1730) ◽  
pp. 944-951 ◽  
Author(s):  
Matt Friedman
Keyword(s):  
Strong Support ◽  
Sister Group ◽  
Lower Jurassic ◽  
Suspension Feeding ◽  
Baleen Whales ◽  
Suspension Feeders ◽  
Lack Of Information ◽  
Bony Fishes ◽  
Body Sizes ◽  
Posidonia Shale

Giant suspension feeders such as mysticete whales, basking and whale sharks, and the extinct (indicated by ‘†’) †pachycormiform teleosts are conspicuous members of modern and fossil marine vertebrate faunas. Whether convergent anatomical features common to these clades arose along similar evolutionary pathways has remained unclear because of a lack of information surrounding the origins of all groups of large-bodied suspension feeders apart from baleen whales. New investigation reveals that the enigmatic ray-finned fish † Ohmdenia , from the Lower Jurassic (Toarcian, 183.0–175.6 Ma) Posidonia Shale Lagerstätte , represents the immediate sister group of edentulous †pachycormiforms, the longest lived radiation of large vertebrate suspension feeders. † Ohmdenia bisects the long morphological branch leading to suspension-feeding †pachycormiforms, providing information on the sequence of anatomical transformations preceding this major ecological shift that can be compared to changes associated with the origin of modern mysticetes. Similarities include initial modifications to jaw geometry associated with the reduction of dentition, followed by the loss of teeth. The evolution of largest body sizes within both radiations occurs only after the apparent onset of microphagy. Comparing the fit of contrasting evolutionary models to functionally relevant morphological measurements for whales and †pachycormiform fishes reveals strong support for a common adaptive peak shared by suspension-feeding members of both clades.

Primitive life habits and adaptive significance of the pelecypod form

Paleobiology ◽  
1976 ◽  
Vol 2 (3) ◽  
pp. 183-190 ◽  
Author(s):  
Michael J. S. Tevesz ◽  
Peter L. McCall
Keyword(s):  
Small Body ◽  
Relative Size ◽  
Mantle Cavity ◽  
Shell Morphology ◽  
Suspension Feeding ◽  
Suspension Feeders ◽  
Body Sizes ◽  
Mode Of Life ◽  
Life Habits ◽  
Soft Bottoms

The typical pelecypod form, long thought to be primitively adaptive to burrowing, is likely to have been originally adaptive to a suspension feeding, epifaunal, possibly crawling mode of life. At small body size (< 1 cm), pelecypods possessing typical burrowing features can function as epifaunal crawlers. Pelecypods arose at small body sizes and are part of a molluscan evolutionary sequence in which relative size of the mantle cavity increased to accommodate a few large gills specialized for suspension feeding.Acquisition of a bivalved shell by ancestral epifaunal suspension feeders may have offered protection from sediment clogging on soft bottoms, additional control over the direction, volume, and rate of water flow through the mantle cavity, more effective protection from predators, and better short-term control of the internal environment. Consideration of invertebrate groups analogous to the pelecypods (Branchiopoda, Cladocera, Ostracoda, Phyllocarida) support the view that the bivalve condition is primarily an adaptation for suspension feeding and predator avoidance in benthic environments.The earliest known pelecypod, Fordilla troyensis Barrande, was not necessarily infaunal just because it had features similar to much larger, Recent burrowers. The size, shell morphology and environment of preservation of F. troyensis all suggest that it is reasonable to envision Cambrian pelecypods as epifaunal suspension feeders, possibly crawling on sedimentary bottoms. Moreover, the sudden Ordovician expansion of pelecypods and increase in individual size may be explained as a result of invasion of the infaunal adaptive zone.

Capture of conspecific planktonic larvae by the suspension-feeding gastropod Crepipatella peruviana: association between adult and larval size

2021 ◽  
Vol 87 (1) ◽  
Author(s):  
G A Rivera-Figueroa ◽  
J A Büchner-Miranda ◽  
L P Salas-Yanquin ◽  
J A Montory ◽  
V M Cubillos ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Larval Mortality ◽  
Feeding Preference ◽  
The Other ◽  
Suspension Feeding ◽  
Adult Size ◽  
Free Living ◽  
Larval Size ◽  
Suspension Feeders ◽  
Planktonic Larvae

ABSTRACT Free-living, planktonic larvae can be vulnerable to capture and ingestion by adult suspension-feeders. This is particularly the case for larvae that settle gregariously in benthic environments where suspension-feeders occur at high densities. Larvae of gregarious suspension-feeding species are at particularly high risk, as adults of their own species often serve as cues for metamorphosis. We conducted laboratory experiments to assess the extent to which adults of the suspension-feeding caenogastropod Crepipatella peruviana would capture and ingest their own larvae. Experiments were conducted with adults of different sizes, with larvae of different ages and sizes, and in the presence or absence of phytoplankton. Adults captured larvae in all experiments. The presence of microalgae in the water did not influence the extent of larval capture. On average, 39% of larvae were captured during the 3-h feeding periods, regardless of adult size. However, up to 34% of the larvae that were captured on the gill were later discarded as pseudofaeces; the other 64% were ingested. The extent of capture by adults was not related to adult size, or to larval size and, thus, to larval age. Our results suggest that the filtration of congeneric larvae by adult C. peruviana is a result of accidental capture rather than a deliberate feeding preference. Such ingestion could, however, still be an important source of larval mortality, especially when the advanced larvae of this species are searching for a suitable substrate for metamorphosis.

scholarly journals Diet of three shark species in the Ecuadorian Pacific, Carcharhinus falciformis, Carcharhinus limbatus and Nasolamia velox

2017 ◽  
Vol 98 (4) ◽  
pp. 927-935 ◽  
Author(s):  
Colombo Estupiñán-Montaño ◽  
Fabian Pacheco-Triviño ◽  
Luis G. Cedeño-Figueroa ◽  
Felipe Galván-Magaña ◽  
Jose F. Estupiñán-Ortiz
Keyword(s):  
Stomach Contents ◽  
Thunnus Albacares ◽  
Shark Species ◽  
Dosidicus Gigas ◽  
Katsuwonus Pelamis ◽  
Carcharhinus Limbatus ◽  
Lack Of Information ◽  
Bony Fishes ◽  
Carcharhinus Falciformis ◽  
Conservation Plans

We analysed the stomach contents of 69 silky sharks Carcharhinus falciformis, 44 blacktip sharks Carcharhinus limbatus and 24 whitenose sharks Nasolamia velox caught in the Ecuadorian Pacific from August 2003 to December 2004. Prey included bony fishes, elasmobranchs, molluscs, crustaceans and turtles, with bony fishes being the most important to the diets of all three sharks, suggesting they are piscivorous predators. Based on the index of relative importance, the C. falciformis diet includes Thunnus albacares, Thunnus sp. and Auxis thazard, as well as some squid, fish and turtles. Similarly, the C. limbatus diet was dominated by T. albacares, Exocoetus monocirrhus, A. thazard, Katsuwonus pelamis, members of the Ophichthidae family and other elasmobranchs. Meanwhile, N. velox consumed mainly Dosidicus gigas, Larimus argenteus, Cynoscion sp. and Lophiodes spilurus. There is little competition for food between these tertiary carnivores: C. limbatus prefers prey from coastal-oceanic habitats; C. falciformis consumes mostly oceanic prey and N. velox focuses on prey from coastal habitats. The lack of information on the biology of sharks in Ecuador hinders the development of appropriate management and conservation plans to protect shark resources. This study increases our knowledge and understanding of sharks in Ecuador, thus contributing to their conservation.

scholarly journals On a remarkable new species of <i>Tharsis</i>, a Late Jurassic teleostean fish from southern Germany: its morphology and phylogenetic relationships

Fossil Record ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 1-23 ◽  
Author(s):  
Gloria Arratia ◽  
Hans-Peter Schultze ◽  
Helmut Tischlinger
Keyword(s):  
New Species ◽  
Late Jurassic ◽  
Strong Support ◽  
Sister Group ◽  
Common Species ◽  
Upper Jurassic ◽  
Morphological Characters ◽  
Morphological Description ◽  
Sister Group Relationship ◽  
Southern Germany

Abstract. A complete morphological description, as preservation permits, is provided for a new Late Jurassic fish species (Tharsis elleri) together with a revision and comparison of some morphological features of Tharsis dubius, one of the most common species from the Solnhofen limestone, southern Germany. An emended diagnosis of the genus Tharsis – now including two species – is presented. The new species is characterized by a combination of morphological characters, such as the presence of a complete sclerotic ring formed by two bones placed anterior and posterior to the eye, a moderately short lower jaw with quadrate-mandibular articulation below the anterior half of the orbit, caudal vertebrae with neural and haemal arches fused to their respective vertebral centrum, and parapophyses fused to their respective centrum. A phylogenetic analysis based on 198 characters and 43 taxa is performed. Following the phylogenetic hypothesis, the sister-group relationship Ascalaboidae plus more advanced teleosts stands above the node of Leptolepis coryphaenoides. Both nodes have strong support among teleosts. The results confirm the inclusion of Ascalabos, Ebertichthys and Tharsis as members of this extinct family. Tharsis elleri n. sp. (LSID urn:lsid:zoobank.org:act:6434E6F5-2DDD-48CF-A2B1-827495FE46E6, date: 13 December 2018) is so far restricted to one Upper Jurassic German locality – Wegscheid Quarry near Schernfeld, Eichstätt – whereas Tharsis dubius is known not only from Wegscheid Quarry, but also from different localities in the Upper Jurassic of Bavaria, Germany, and Cerin in France.

scholarly journals Placozoa and Cnidaria are sister taxa

2017 ◽  
Author(s):  
Christopher E. Laumer ◽  
Harald Gruber-Vodicka ◽  
Michael G. Hadfield ◽  
Vicki B. Pearse ◽  
Ana Riesgo ◽  
...  
Keyword(s):  
Strong Support ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Large Dataset ◽  
Animal Evolution ◽  
Phylogenetic Placement ◽  
The Matrix ◽  
Show Evidence ◽  
Animal Phylogeny ◽  
Reduced Forms

AbstractThe phylogenetic placement of the morphologically simple placozoans is crucial to understanding the evolution of complex animal traits. Here, we examine the influence of adding new genomes from placozoans to a large dataset designed to study the deepest splits in the animal phylogeny. Using site-heterogeneous substitution models, we show that it is possible to obtain strong support, in both amino acid and reduced-alphabet matrices, for either a sister-group relationship between Cnidaria and Placozoa, or for Cnidaria and Bilateria (=Planulozoa), also seen in most published work to date, depending on the orthologues selected to construct the matrix. We demonstrate that a majority of genes show evidence of compositional heterogeneity, and that the support for Planulozoa can be assigned to this source of systematic error. In interpreting this placozoan-cnidarian clade, we caution against a peremptory reading of placozoans as secondarily reduced forms of little relevance to broader discussions of early animal evolution.

Phylogenetic relationships in the monocot order Commelinales, with a focus on PhilydraceaeThis paper is one of a selection of papers published in the Special Issue on Systematics Research.

Botany ◽  
2008 ◽  
Vol 86 (7) ◽  
pp. 719-731 ◽  
Author(s):  
Jeffery M. Saarela ◽  
Peter J. Prentis ◽  
Hardeep S. Rai ◽  
Sean W. Graham
Keyword(s):  
Phylogenetic Relationships ◽  
Strong Support ◽  
Sister Group ◽  
Higher Order ◽  
Special Issue ◽  
Likelihood Methods ◽  
The Family ◽  
Selection Of

To characterize higher-order phylogenetic relationships among the five families of Commelinales, we surveyed multiple plastid loci from exemplar taxa sampled broadly from the order, and from other major monocot lineages. Phylogenetic inferences in Commelinales using parsimony and likelihood methods are congruent, and we find strong support for most aspects of higher-order relationship in the order. We obtain moderately strong support for the local placement of Philydraceae, a family whose position has proven particularly difficult to infer in previous studies. Commelinaceae and Hanguanaceae are sister taxa, and together they are the sister group of a clade consisting of Haemodoraceae, Philydraceae, and Pontederiaceae; Haemodoraceae and Pontederiaceae are also sister taxa. Our sampling of Philydraceae includes all three or four genera in the family; we identify Philydrella as the sister group of a Helmholtzia–Philydrum clade, a resolution that is potentially consistent with several aspects of morphology.

New metrics to differentiate species ofStenopterygius(Reptilia: Ichthyosauria) from the Lower Jurassic of southwestern Germany

2012 ◽  
Vol 86 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Erin E. Maxwell
Keyword(s):  
Soft Tissue ◽  
Multivariate Analyses ◽  
Research Effort ◽  
Measurement Data ◽  
Body Cavity ◽  
Lower Jurassic ◽  
The Body ◽  
Marine Reptiles ◽  
The World ◽  
Posidonia Shale

Ichthyosaurs represent one of the most highly specialized lineages of marine reptiles, but our understanding of the evolution of this group is based on specimens found at a surprisingly small number of stratigraphic intervals and localities. The Lower Jurassic (Toarcian) Posidonia Shale of southwestern Germany is one of the richest ichthyosaur-bearing formations in the world and has produced thousands of skeletons, including specimens with preserved soft tissue, and fetal remains inside the body cavity. The most abundant ichthyosaur genus in the Posidonia Shale isStenopterygius. In spite of almost 200 years of research effort, the number of species in this genus is still a point of active disagreement in the literature. Here, bivariate and multivariate analyses are used to classify both articulated and disarticulated skeletons to the level of species, using measurement data from individual cranial and postcranial elements. Unlike previous classification attempts, this technique pinpoints ontogenetically conserved differences in size and proportion between the species, and so can be applied to adult, subadult, and neonatal specimens. Using this method, three species ofStenopterygius, S. quadriscissus, S. triscissus, andS. uniterare differentiated.

A Phylogenetic Analysis and Taxonomic Revision of Bartonia (Gentianaceae: Gentianeae), Based on Molecular and Morphological Evidence

2009 ◽  
Vol 34 (1) ◽  
pp. 162-172 ◽  
Author(s):  
Katherine G. Mathews ◽  
Niall Dunne ◽  
Emily York ◽  
Lena Struwe
Keyword(s):  
Phylogenetic Analyses ◽  
Strong Support ◽  
Taxonomic Revision ◽  
Sister Group ◽  
Species Boundaries ◽  
Morphological Evidence ◽  
Phylogenetic Study ◽  
Sister Group Relationship ◽  
Internal Transcribed Spacer Region ◽  
Test Species

A phylogenetic study and taxonomic revision of the four currently accepted species of Bartonia (Gentianaceae, subtribe Swertiinae) were conducted in order to test species boundaries and interspecific relationships. Species boundaries were examined based on measurements of key quantitative and qualitative morphological characters as given in the original descriptions. Phylogenetic analyses were performed using molecular data from the nuclear internal transcribed spacer region and chloroplast DNA (trnL intron through the trnL-F spacer), separately and combined using parsimony and Bayesian methodologies, incorporating outgroups from subtribes Swertiinae and Gentianinae. The morphological study revealed that characters of one species, B. texana, represent a subset of the morphological variation found within B. paniculata, but that B. paniculata, B. verna, and B. virginica could all be separated from one another. The molecular phylogenetic analyses all found B. texana to nest in a clade with the two recognized subspecies of B. paniculata (subsp. paniculata and subsp. iodandra), making the latter paraphyletic. Bartonia texana is here reduced to subspecific rank, as Bartonia paniculata subsp. texana. Also, the phylogenetic analyses showed strong support for a sister group relationship between B. verna and B. virginica, as opposed to between B. paniculata and B. virginica as has been previously suggested.

Inference of higher-order conifer relationships from a multi-locus plastid data setThis paper is one of a selection of papers published in the Special Issue on Systematics Research.

Botany ◽  
2008 ◽  
Vol 86 (7) ◽  
pp. 658-669 ◽  
Author(s):  
Hardeep S. Rai ◽  
Patrick A. Reeves ◽  
Rod Peakall ◽  
Richard G. Olmstead ◽  
Sean W. Graham
Keyword(s):  
Strong Support ◽  
Sister Group ◽  
Higher Order ◽  
Bootstrap Support ◽  
Sister Group Relationship ◽  
Ribosomal Protein Genes ◽  
Conifer Species ◽  
Noncoding Regions ◽  
Selection Of

We reconstructed the broad backbone of conifer phylogeny from a survey of 15–17 plastid loci and associated noncoding regions from exemplar conifer species. Parsimony and likelihood analyses recover the same higher-order relationships, and we find strong support for most of the deep splits in conifer phylogeny, including those within our two most heavily sampled families, Araucariaceae and Cupressaceae. Our findings are broadly congruent with other recent studies, and are inferred with comparable or improved bootstrap support. The deepest phylogenetic split in conifers is inferred to be between Pinaceae and all other conifers (Cupressophyta). Our current gene and taxon sampling does not support a relationship between Pinaceae and Gnetales, observed in some published studies. Within the Cupressophyta clade, we infer well-supported relationships among Cephalotaxaceae, Cupressaceae, Sciadopityaceae, and Taxaceae. Our data support recent moves to recognize Cephalotaxus under Taxaceae, and we find strong support for a sister-group relationship between the two predominantly southern hemisphere conifer families, Araucariaceae and Podocarpaceae. A local hotspot of indel evolution shared by the latter two conifer families is identified in the coding portion of one of the plastid ribosomal protein genes. The removal of the most rapidly evolving plastid characters, as defined using a likelihood-based classification of substitution rates for the taxa considered here, is shown to have little to no effect on our inferences of higher-order conifer relationships.

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