Bivalves are an ancient and ubiquitous group of aquatic invertebrates with an estimated 10 000–20... more Bivalves are an ancient and ubiquitous group of aquatic invertebrates with an estimated 10 000–20 000 living species. They are economically significant as a human food source, and ecologically important given their biomass and effects on communities. Their phylogenetic relationships have been studied for decades, and their unparalleled fossil record extends from the Cambrian to the Recent. Nevertheless, a robustly supported phylogeny of the deepest nodes, needed to fully exploit the bivalves as a model for testing macroevolutionary theories, is lacking. Here, we present the first phylogenomic approach for this important group of molluscs, including novel transcriptomic data for 31 bivalves obtained through an RNA-seq approach, and analyse these data with published genomes and transcriptomes of other bivalves plus outgroups. Our results provide a well-resolved, robust phylogenetic backbone for Bivalvia with all major lineages delineated, addressing long-standing questions about the monophyly of Protobranchia and Heterodonta, and resolving the position of particular groups such as Palaeoheterodonta, Archiheterodonta and Anomalodesmata. This now fully resolved backbone demonstrates that genomic approaches using hundreds of genes are feasible for resolving phylogenetic questions in bivalves and other animals
This glossary defines terms relating to bivalve morphology, anatomy, physiology, ecology, reprodu... more This glossary defines terms relating to bivalve morphology, anatomy, physiology, ecology, reproduction, taxonomy, evolution, phylogenetics, mineral and organic composition, shell microstructure, and fossil preservation.
Page 1. PINCTADA LONGISQUAMOSA (DUNKER, 1852) (BIVALVIA: PTERIIDAE), AN UNRECOGNIZED PEARL OYSTER... more Page 1. PINCTADA LONGISQUAMOSA (DUNKER, 1852) (BIVALVIA: PTERIIDAE), AN UNRECOGNIZED PEARL OYSTER IN THE WESTERN ATLANTIC Paula M. Mikkelsen1,Ilya Tëmkin2, Rüdiger Bieler3 & William G. Lyons4 ABSTRACT ...
Robert Robertson (1934−2018) was systematic malacologist, natural historian, and reproductive bio... more Robert Robertson (1934−2018) was systematic malacologist, natural historian, and reproductive biologist, focusing on marine gastropods and based at the Academy of Natural Sciences in Philadelphia (ANSP) for most of his career. An account of his professional life is presented, based in part on a brief autobiography here included. Lists of his 142 publications (published and unpublished, formal and informal) and 13 taxa, as well as taxa named for him and publications written about him, are provided
Molecular phylogenetics and evolution, Feb 10, 2016
The systematics of the molluscan class Bivalvia are explored using a 5-gene Sanger-based approach... more The systematics of the molluscan class Bivalvia are explored using a 5-gene Sanger-based approach including the largest taxon sampling to date, encompassing 219 ingroup species spanning 93 (or 82%) of the 113 currently accepted bivalve families. This study was designed to populate the bivalve Tree of Life at the family level and to place many genera into a clear phylogenetic context, but also pointing to several major clades where taxonomic work is sorely needed. Despite not recovering monophyly of Bivalvia or Protobranchia-as in most previous Sanger-based approaches to bivalve phylogeny-our study provides increased resolution in many higher-level clades, and supports the monophyly of Autobranchia, Pteriomorphia, Heteroconchia, Palaeoheterodonta, Heterodonta, Archiheterodonta, Euheterodonta, Anomalodesmata, Imparidentia, and Neoheterodontei, in addition to many other lower clades. However, deep nodes within some of these clades, especially Pteriomorphia and Imparidentia, could not b...
... Bartsch, President Henry A. Pilsbry, Secretary-Treasurer Norman Lermond, Financial Secretary ... more ... Bartsch, President Henry A. Pilsbry, Secretary-Treasurer Norman Lermond, Financial Secretary Imogene C. Robertson, and Councilor Calvin Goodrich. ... Bottom left: then-President PaulaMikkelsen and Auctioneer Paul Callomon at the AMS auction during the World Congress of ...
ABSTRACT Periglypta listeri (J. E. Gray, 1838), one of the largest and most distinctive western A... more ABSTRACT Periglypta listeri (J. E. Gray, 1838), one of the largest and most distinctive western Atlantic venerids, and the only Atlantic member of the genus, is redescribed based on original mate-rial from the Florida Keys, museum specimens, and literature records. Conchologically, this species agrees with previously described venerids in having a well-developed escutcheon and lunule, and a hinge with three cardinal teeth in each valve. Within the genus, it is unique in having internal purplish brown coloration, and in the frequent presence of a purplish brown "hinge dot" on the anterior lateral tooth. This is the first anatomical study for any species in the genus Periglypta, and the most complete so far for any member of Venerinae. Periglypta listeri agrees with previously described venerids in most anatomical characteristics, and notably features an undulating mantle edge that can close in "zipper" fashion, tentacles at the anterior mantle edge, and branching tentacles at the tips of the unfused siphons, type B mantle fusion, type C(2) ctenidia, and a type V stomach. Although empty shells are commonly collected, P. listeri unusually (for venerids) lives cryptically in rubble or sand among rocks, and/or in reef settings. Thus far, the presence of an anterior lateral hinge tooth is the sole morphological feature separating the subfamily Venerinae from the closely allied Chioninae.
... In addition, I would strongly recommend this book to all malacologists and shell collectors. ... more ... In addition, I would strongly recommend this book to all malacologists and shell collectors. It just might entice them to take the plunge into the exciting, if not tumultuous, world of bivalvetaxonomy."--Paul Valentich-Scott, The Festivus. Endorsements: ...
ABSTRACT Despite universal recognition of coral reefs as the 'ocean's rainforest,... more ABSTRACT Despite universal recognition of coral reefs as the 'ocean's rainforest,' the focus of conservation is largely restricted to cnidarians, fish, larger sponges, and macroalgae. These span a wide taxonomic range and can be monitored non-invasively. But a biodiversity picture based on so few taxa is dismally incomplete. As in the rainforest, the overwhelming majority of species and clades on the reef are cryptic. Worms, mollusks, echinoderms, and crustaceans are numerically dominant, contribute to the trophic underpinning, and play pivotal ecological roles. Other than a few charismatic species (e.g., starfish, tube worms, conchs), they are underestimated and overassumed. Proper inventory of such taxa requires factors not routinely employed in conservation: physical sampling and systematic expertise. Yet scientifically robust results can be achieved with minimal damage and investment, and lead to recognition of key species, for which monitoring schemes can be developed. Examples of recent surveys by systematists are provided, involving echinoderms, mollusks, crustaceans, and worms from a variety of marine habitats, and each showing significant results. Despite this evidence of success, acquiring systematic expertise for inventorying marine invertebrates continues to be a limiting factor. After decades of de-emphasizing systematics, the cohort of trained systematists is aging and facing non-replacement, even in museums where extensive specimen collections, laboratories, and libraries provide the best available support for systematic work. In today's climate of biodiversity interest, new initiatives are attempting to reverse this trend. National Science Foundation's PEET [Partnerships for Enhancing Expertise in Taxonomy] Program is providing resources for training the next generation of taxonomists working on poorly known groups. At the international level, initiatives such as DIVERSITAS' Systematics Agenda 2000 International Program are supporting new agendas to document reef biodiversity and promote systematic inventory. The Convention on Biological Diversity is calling for more systematic inventories to facilitate their goals of conservation and sustainable development. Programmatic and financial support for inventories by national, regional, and local conservation and monitoring agencies are the next requirement.
Bivalves are an ancient and ubiquitous group of aquatic invertebrates with an estimated 10 000–20... more Bivalves are an ancient and ubiquitous group of aquatic invertebrates with an estimated 10 000–20 000 living species. They are economically significant as a human food source, and ecologically important given their biomass and effects on communities. Their phylogenetic relationships have been studied for decades, and their unparalleled fossil record extends from the Cambrian to the Recent. Nevertheless, a robustly supported phylogeny of the deepest nodes, needed to fully exploit the bivalves as a model for testing macroevolutionary theories, is lacking. Here, we present the first phylogenomic approach for this important group of molluscs, including novel transcriptomic data for 31 bivalves obtained through an RNA-seq approach, and analyse these data with published genomes and transcriptomes of other bivalves plus outgroups. Our results provide a well-resolved, robust phylogenetic backbone for Bivalvia with all major lineages delineated, addressing long-standing questions about the monophyly of Protobranchia and Heterodonta, and resolving the position of particular groups such as Palaeoheterodonta, Archiheterodonta and Anomalodesmata. This now fully resolved backbone demonstrates that genomic approaches using hundreds of genes are feasible for resolving phylogenetic questions in bivalves and other animals
This glossary defines terms relating to bivalve morphology, anatomy, physiology, ecology, reprodu... more This glossary defines terms relating to bivalve morphology, anatomy, physiology, ecology, reproduction, taxonomy, evolution, phylogenetics, mineral and organic composition, shell microstructure, and fossil preservation.
Page 1. PINCTADA LONGISQUAMOSA (DUNKER, 1852) (BIVALVIA: PTERIIDAE), AN UNRECOGNIZED PEARL OYSTER... more Page 1. PINCTADA LONGISQUAMOSA (DUNKER, 1852) (BIVALVIA: PTERIIDAE), AN UNRECOGNIZED PEARL OYSTER IN THE WESTERN ATLANTIC Paula M. Mikkelsen1,Ilya Tëmkin2, Rüdiger Bieler3 & William G. Lyons4 ABSTRACT ...
Robert Robertson (1934−2018) was systematic malacologist, natural historian, and reproductive bio... more Robert Robertson (1934−2018) was systematic malacologist, natural historian, and reproductive biologist, focusing on marine gastropods and based at the Academy of Natural Sciences in Philadelphia (ANSP) for most of his career. An account of his professional life is presented, based in part on a brief autobiography here included. Lists of his 142 publications (published and unpublished, formal and informal) and 13 taxa, as well as taxa named for him and publications written about him, are provided
Molecular phylogenetics and evolution, Feb 10, 2016
The systematics of the molluscan class Bivalvia are explored using a 5-gene Sanger-based approach... more The systematics of the molluscan class Bivalvia are explored using a 5-gene Sanger-based approach including the largest taxon sampling to date, encompassing 219 ingroup species spanning 93 (or 82%) of the 113 currently accepted bivalve families. This study was designed to populate the bivalve Tree of Life at the family level and to place many genera into a clear phylogenetic context, but also pointing to several major clades where taxonomic work is sorely needed. Despite not recovering monophyly of Bivalvia or Protobranchia-as in most previous Sanger-based approaches to bivalve phylogeny-our study provides increased resolution in many higher-level clades, and supports the monophyly of Autobranchia, Pteriomorphia, Heteroconchia, Palaeoheterodonta, Heterodonta, Archiheterodonta, Euheterodonta, Anomalodesmata, Imparidentia, and Neoheterodontei, in addition to many other lower clades. However, deep nodes within some of these clades, especially Pteriomorphia and Imparidentia, could not b...
... Bartsch, President Henry A. Pilsbry, Secretary-Treasurer Norman Lermond, Financial Secretary ... more ... Bartsch, President Henry A. Pilsbry, Secretary-Treasurer Norman Lermond, Financial Secretary Imogene C. Robertson, and Councilor Calvin Goodrich. ... Bottom left: then-President PaulaMikkelsen and Auctioneer Paul Callomon at the AMS auction during the World Congress of ...
ABSTRACT Periglypta listeri (J. E. Gray, 1838), one of the largest and most distinctive western A... more ABSTRACT Periglypta listeri (J. E. Gray, 1838), one of the largest and most distinctive western Atlantic venerids, and the only Atlantic member of the genus, is redescribed based on original mate-rial from the Florida Keys, museum specimens, and literature records. Conchologically, this species agrees with previously described venerids in having a well-developed escutcheon and lunule, and a hinge with three cardinal teeth in each valve. Within the genus, it is unique in having internal purplish brown coloration, and in the frequent presence of a purplish brown "hinge dot" on the anterior lateral tooth. This is the first anatomical study for any species in the genus Periglypta, and the most complete so far for any member of Venerinae. Periglypta listeri agrees with previously described venerids in most anatomical characteristics, and notably features an undulating mantle edge that can close in "zipper" fashion, tentacles at the anterior mantle edge, and branching tentacles at the tips of the unfused siphons, type B mantle fusion, type C(2) ctenidia, and a type V stomach. Although empty shells are commonly collected, P. listeri unusually (for venerids) lives cryptically in rubble or sand among rocks, and/or in reef settings. Thus far, the presence of an anterior lateral hinge tooth is the sole morphological feature separating the subfamily Venerinae from the closely allied Chioninae.
... In addition, I would strongly recommend this book to all malacologists and shell collectors. ... more ... In addition, I would strongly recommend this book to all malacologists and shell collectors. It just might entice them to take the plunge into the exciting, if not tumultuous, world of bivalvetaxonomy."--Paul Valentich-Scott, The Festivus. Endorsements: ...
ABSTRACT Despite universal recognition of coral reefs as the 'ocean's rainforest,... more ABSTRACT Despite universal recognition of coral reefs as the 'ocean's rainforest,' the focus of conservation is largely restricted to cnidarians, fish, larger sponges, and macroalgae. These span a wide taxonomic range and can be monitored non-invasively. But a biodiversity picture based on so few taxa is dismally incomplete. As in the rainforest, the overwhelming majority of species and clades on the reef are cryptic. Worms, mollusks, echinoderms, and crustaceans are numerically dominant, contribute to the trophic underpinning, and play pivotal ecological roles. Other than a few charismatic species (e.g., starfish, tube worms, conchs), they are underestimated and overassumed. Proper inventory of such taxa requires factors not routinely employed in conservation: physical sampling and systematic expertise. Yet scientifically robust results can be achieved with minimal damage and investment, and lead to recognition of key species, for which monitoring schemes can be developed. Examples of recent surveys by systematists are provided, involving echinoderms, mollusks, crustaceans, and worms from a variety of marine habitats, and each showing significant results. Despite this evidence of success, acquiring systematic expertise for inventorying marine invertebrates continues to be a limiting factor. After decades of de-emphasizing systematics, the cohort of trained systematists is aging and facing non-replacement, even in museums where extensive specimen collections, laboratories, and libraries provide the best available support for systematic work. In today's climate of biodiversity interest, new initiatives are attempting to reverse this trend. National Science Foundation's PEET [Partnerships for Enhancing Expertise in Taxonomy] Program is providing resources for training the next generation of taxonomists working on poorly known groups. At the international level, initiatives such as DIVERSITAS' Systematics Agenda 2000 International Program are supporting new agendas to document reef biodiversity and promote systematic inventory. The Convention on Biological Diversity is calling for more systematic inventories to facilitate their goals of conservation and sustainable development. Programmatic and financial support for inventories by national, regional, and local conservation and monitoring agencies are the next requirement.
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Papers by Paula M Mikkelsen