Paul Selden | University of Kansas (original) (raw)
Papers by Paul Selden
Transactions of the Royal Society of Edinburgh: Earth Sciences, 1992
The fossil ricinuleids are described, and their systematic relationships revised, based on a stud... more The fossil ricinuleids are described, and their systematic relationships revised, based on a study of all British and American specimens. Phylogenetic analysis, utilising a new character set, indicates a probable basal dichotomy between the fossil and extant forms. The order is divided into two new suborders: Neoricinulei subordo, nov., for the extant genera, and Palaeoricinulei subordo. nov., for the fossil forms. Two new genera are erected: Amarixys gen. nov. for Curculioides gracilis (Petrunkevitch, 1945) and A. stellaris sp. nov., ...
Journal of Afrotropical Zoology, 2005
Amber, fossilized tree resin, is a well-known Fossil- Lagerstätte (an exceptional occurrence of w... more Amber, fossilized tree resin, is a well-known Fossil- Lagerstätte (an exceptional occurrence of well-preserved fossil biota). Living animals become trapped in the sticky resin when it is exuded by the tree and subsequently engulfed by more resin (eg Penney 2002), which hardens in contact with the air. Reasons for trees to exude resin are not well known and may be related to wound repair, but many insects, and therefore their predators, are attracted to resin seeps. Following burial in sediment, diagenetic processes turn the resin into the fossilized amber. Resin ...
Journal of Afrotropical Zoology, 2005
Amber, fossilized tree resin, is a well-known Fossil- Lagerstätte (an exceptional occurrence of w... more Amber, fossilized tree resin, is a well-known Fossil- Lagerstätte (an exceptional occurrence of well-preserved fossil biota). Living animals become trapped in the sticky resin when it is exuded by the tree and subsequently engulfed by more resin (eg Penney 2002), which hardens in contact with the air. Reasons for trees to exude resin are not well known and may be related to wound repair, but many insects, and therefore their predators, are attracted to resin seeps. Following burial in sediment, diagenetic processes turn the resin into the fossilized amber. Resin ...
Palaeontology, Jun 1, 1991
Abstract: The oldest known spider, from the Devonian (Givelian) of Gilboa. New York, is Atlercopu... more Abstract: The oldest known spider, from the Devonian (Givelian) of Gilboa. New York, is Atlercopus fimbriunguis (Shear. Sclden and Rolfc). parts of which were originally described as a trigonotarbid. possibly of the genus Gelasinotarbus. Previous reports of Devonian spider fossils, from the Lower Emsian of Alken-an-der-Moscl. Germany, and the Pragian of Rhynie. Scotland, are shown to be erroneous identifications. Atlercopus is placed as sister-laxon to all living spiders, on the basis of characters of the spinneret and the arrangement ...
Palaeontology, Jun 1, 1991
Abstract: The oldest known spider, from the Devonian (Givelian) of Gilboa. New York, is Atlercopu... more Abstract: The oldest known spider, from the Devonian (Givelian) of Gilboa. New York, is Atlercopus fimbriunguis (Shear. Sclden and Rolfc). parts of which were originally described as a trigonotarbid. possibly of the genus Gelasinotarbus. Previous reports of Devonian spider fossils, from the Lower Emsian of Alken-an-der-Moscl. Germany, and the Pragian of Rhynie. Scotland, are shown to be erroneous identifications. Atlercopus is placed as sister-laxon to all living spiders, on the basis of characters of the spinneret and the arrangement ...
Palaeoworld, 2020
A new shell-bearing organism with preserved soft tissue, Armilimax pauljamisoni n. gen. n. sp., i... more A new shell-bearing organism with preserved soft tissue, Armilimax pauljamisoni n. gen. n. sp., is reported from the middle Cambrian (Miaolingian: Wuliuan) Miners Hollow locality of the Spence Shale of northern Utah. The described organism is known from a single articulated specimen and preserves a prominent shell, a slug-like body, as well as a U-shaped digestive tract. Its overall appearance is similar to halkieriids, but it does not preserve sclerites. The possible affinities of the new taxon and potential reasons for the presence of a U-shaped gut are discussed. Armilimax pauljamisoni is the first shell-bearing animal of its kind from the Great Basin and extends the diversity of body plans in the Spence Shale Fossil-Lagerstätte.
T o date, 47,001 living and 1,342 extinct species of spider (Araneae) have been described (http:/... more T o date, 47,001 living and 1,342 extinct species of spider (Araneae) have been described (http://wsc.nmbe.ch/). The oldest fossils currently assigned to this group date from the late Carboniferous (approximately 305 million years ago (Ma)) 1,2 , while an earlier report of a Devonian (around 380 Ma) spider 3,4 was later reinterpreted as belonging to an extinct arachnid order named Uraraneida 5. Uraraneids are also known from the Permian (approximately 275 Ma) and resemble spiders, but possess a long, flagellate telson. Another key difference is that uraraneids have spigots for producing silk 3 , but lack the spinnerets that facilitate a more precise deposition of the threads 6,7. Phylogenetic analysis 4,8 often recovers spiders as the sister group to a clade comprising whip spiders (Amblypygi), whip scorpions (Thelyphonida) and schizo-mids (Schizomida). Spiders and their relatives are known as the Pantetrapulmonata and are characterized by a ground pattern of two pairs of book lungs. Whip scorpions and schizomids express a flagelliform telson, a character also seen in the non-tetrapulmonate order Palpigradi, a group that has been postulated as retaining several plesiomorphic character states among arachnids 9. Key autapo-morphies of spiders, which presumably underlie their high modern species diversity, are silk glands opening via spigots on spinnerets, chelicerae with venom glands and male pedipalps modified for sperm transfer. Male spiders possess additional epiandrous silk spigots anterior to their genital opening. Spiders are conventionally divided into two suborders 6. Mesothelae retain opisthosomal tergites and the spinnerets are in the middle of the ventral opist-hosoma. Opisthothelae (Mygalomorphae and Araneomorphae) lack most external evidence of opisthosomal segmentation and the spinnerets emerge towards the posterior of the body. Recently, a handful of Palaeozoic fossils have been placed close to spider origins through preserving at least some of their diagnostic features.
Mass extinctions have altered the trajectory of evolution a number of times over the Phanerozoic.... more Mass extinctions have altered the trajectory of evolution a number of times over the Phanerozoic. During these periods of biotic upheaval a different selective regime appears to operate, although it is still unclear whether consistent survivorship rules apply across different extinction events. We compare variations in diversity and disparity across the evolutionary history of a major Paleozoic arthropod group, the Eurypterida. Using these data, we explore the group's transition from a successful, dynamic clade to a stagnant persistent lineage, pinpointing the Devonian as the period during which this evolutionary regime shift occurred. The late Devonian biotic crisis is potentially unique among the " Big Five " mass extinctions in exhibiting a drop in speciation rates rather than an increase in extinction. Our study reveals eurypterids show depressed speciation rates throughout the Devonian but no abnormal peaks in extinction. Loss of morphospace occupation is random across all Paleozoic extinction events; however, differential origination during the Devonian results in a migration and subsequent stagnation of occupied morphospace. This shift appears linked to an ecological transition from euryhaline taxa to freshwater species with low morphological diversity alongside a decrease in endemism. These results demonstrate the importance of the Devonian biotic crisis in reshaping Paleozoic ecosystems.
Systematic Parasitology, 1997
African Invertebrates, 2009
A new assemblage of arthropod cuticles from Upper Silurian rocks in Shropshire, England, includes... more A new assemblage of arthropod cuticles from Upper Silurian rocks in Shropshire, England, includes at least two centipedes and a trigonotarbid arachnid. This unequivocal terrestrial fauna from the Silurian constitutes the earliest direct record of land animals. The presence of predatory arthropods suggests that complex terrestrial ecosystems were in place by the late Silurian (414>< 10 years before present) and that the animal invasion of the land occurred earlier than was previously thought.
Palaios, Jul 1, 2012
Short chains of discoidal, rarely spheroidal, structures, recovered by acid maceration of Lower D... more Short chains of discoidal, rarely spheroidal, structures, recovered by acid maceration of Lower Devonian (Lochkovian) siltstones from the Welsh Borderland are interpreted as coprolites because they comprise comminuted or homogenized tissues. They are placed in a new species of the ichnogenus Lancifaex. Tissues include the smooth and banded tubes of Nematasketum, a close ally of Prototaxites, and rarer cuticles of Nematothallus and Cosmochlaina. All these taxa have been assigned to an extinct class, ...
Journal of the American Society …, Jan 1, 2010
Http Dx Doi Org 10 1080 14772019 2015 1018969, Mar 24, 2015
Journal of Paleontology, 2015
Transactions of the Royal Society of Edinburgh: Earth Sciences, 1992
The fossil ricinuleids are described, and their systematic relationships revised, based on a stud... more The fossil ricinuleids are described, and their systematic relationships revised, based on a study of all British and American specimens. Phylogenetic analysis, utilising a new character set, indicates a probable basal dichotomy between the fossil and extant forms. The order is divided into two new suborders: Neoricinulei subordo, nov., for the extant genera, and Palaeoricinulei subordo. nov., for the fossil forms. Two new genera are erected: Amarixys gen. nov. for Curculioides gracilis (Petrunkevitch, 1945) and A. stellaris sp. nov., ...
Journal of Afrotropical Zoology, 2005
Amber, fossilized tree resin, is a well-known Fossil- Lagerstätte (an exceptional occurrence of w... more Amber, fossilized tree resin, is a well-known Fossil- Lagerstätte (an exceptional occurrence of well-preserved fossil biota). Living animals become trapped in the sticky resin when it is exuded by the tree and subsequently engulfed by more resin (eg Penney 2002), which hardens in contact with the air. Reasons for trees to exude resin are not well known and may be related to wound repair, but many insects, and therefore their predators, are attracted to resin seeps. Following burial in sediment, diagenetic processes turn the resin into the fossilized amber. Resin ...
Journal of Afrotropical Zoology, 2005
Amber, fossilized tree resin, is a well-known Fossil- Lagerstätte (an exceptional occurrence of w... more Amber, fossilized tree resin, is a well-known Fossil- Lagerstätte (an exceptional occurrence of well-preserved fossil biota). Living animals become trapped in the sticky resin when it is exuded by the tree and subsequently engulfed by more resin (eg Penney 2002), which hardens in contact with the air. Reasons for trees to exude resin are not well known and may be related to wound repair, but many insects, and therefore their predators, are attracted to resin seeps. Following burial in sediment, diagenetic processes turn the resin into the fossilized amber. Resin ...
Palaeontology, Jun 1, 1991
Abstract: The oldest known spider, from the Devonian (Givelian) of Gilboa. New York, is Atlercopu... more Abstract: The oldest known spider, from the Devonian (Givelian) of Gilboa. New York, is Atlercopus fimbriunguis (Shear. Sclden and Rolfc). parts of which were originally described as a trigonotarbid. possibly of the genus Gelasinotarbus. Previous reports of Devonian spider fossils, from the Lower Emsian of Alken-an-der-Moscl. Germany, and the Pragian of Rhynie. Scotland, are shown to be erroneous identifications. Atlercopus is placed as sister-laxon to all living spiders, on the basis of characters of the spinneret and the arrangement ...
Palaeontology, Jun 1, 1991
Abstract: The oldest known spider, from the Devonian (Givelian) of Gilboa. New York, is Atlercopu... more Abstract: The oldest known spider, from the Devonian (Givelian) of Gilboa. New York, is Atlercopus fimbriunguis (Shear. Sclden and Rolfc). parts of which were originally described as a trigonotarbid. possibly of the genus Gelasinotarbus. Previous reports of Devonian spider fossils, from the Lower Emsian of Alken-an-der-Moscl. Germany, and the Pragian of Rhynie. Scotland, are shown to be erroneous identifications. Atlercopus is placed as sister-laxon to all living spiders, on the basis of characters of the spinneret and the arrangement ...
Palaeoworld, 2020
A new shell-bearing organism with preserved soft tissue, Armilimax pauljamisoni n. gen. n. sp., i... more A new shell-bearing organism with preserved soft tissue, Armilimax pauljamisoni n. gen. n. sp., is reported from the middle Cambrian (Miaolingian: Wuliuan) Miners Hollow locality of the Spence Shale of northern Utah. The described organism is known from a single articulated specimen and preserves a prominent shell, a slug-like body, as well as a U-shaped digestive tract. Its overall appearance is similar to halkieriids, but it does not preserve sclerites. The possible affinities of the new taxon and potential reasons for the presence of a U-shaped gut are discussed. Armilimax pauljamisoni is the first shell-bearing animal of its kind from the Great Basin and extends the diversity of body plans in the Spence Shale Fossil-Lagerstätte.
T o date, 47,001 living and 1,342 extinct species of spider (Araneae) have been described (http:/... more T o date, 47,001 living and 1,342 extinct species of spider (Araneae) have been described (http://wsc.nmbe.ch/). The oldest fossils currently assigned to this group date from the late Carboniferous (approximately 305 million years ago (Ma)) 1,2 , while an earlier report of a Devonian (around 380 Ma) spider 3,4 was later reinterpreted as belonging to an extinct arachnid order named Uraraneida 5. Uraraneids are also known from the Permian (approximately 275 Ma) and resemble spiders, but possess a long, flagellate telson. Another key difference is that uraraneids have spigots for producing silk 3 , but lack the spinnerets that facilitate a more precise deposition of the threads 6,7. Phylogenetic analysis 4,8 often recovers spiders as the sister group to a clade comprising whip spiders (Amblypygi), whip scorpions (Thelyphonida) and schizo-mids (Schizomida). Spiders and their relatives are known as the Pantetrapulmonata and are characterized by a ground pattern of two pairs of book lungs. Whip scorpions and schizomids express a flagelliform telson, a character also seen in the non-tetrapulmonate order Palpigradi, a group that has been postulated as retaining several plesiomorphic character states among arachnids 9. Key autapo-morphies of spiders, which presumably underlie their high modern species diversity, are silk glands opening via spigots on spinnerets, chelicerae with venom glands and male pedipalps modified for sperm transfer. Male spiders possess additional epiandrous silk spigots anterior to their genital opening. Spiders are conventionally divided into two suborders 6. Mesothelae retain opisthosomal tergites and the spinnerets are in the middle of the ventral opist-hosoma. Opisthothelae (Mygalomorphae and Araneomorphae) lack most external evidence of opisthosomal segmentation and the spinnerets emerge towards the posterior of the body. Recently, a handful of Palaeozoic fossils have been placed close to spider origins through preserving at least some of their diagnostic features.
Mass extinctions have altered the trajectory of evolution a number of times over the Phanerozoic.... more Mass extinctions have altered the trajectory of evolution a number of times over the Phanerozoic. During these periods of biotic upheaval a different selective regime appears to operate, although it is still unclear whether consistent survivorship rules apply across different extinction events. We compare variations in diversity and disparity across the evolutionary history of a major Paleozoic arthropod group, the Eurypterida. Using these data, we explore the group's transition from a successful, dynamic clade to a stagnant persistent lineage, pinpointing the Devonian as the period during which this evolutionary regime shift occurred. The late Devonian biotic crisis is potentially unique among the " Big Five " mass extinctions in exhibiting a drop in speciation rates rather than an increase in extinction. Our study reveals eurypterids show depressed speciation rates throughout the Devonian but no abnormal peaks in extinction. Loss of morphospace occupation is random across all Paleozoic extinction events; however, differential origination during the Devonian results in a migration and subsequent stagnation of occupied morphospace. This shift appears linked to an ecological transition from euryhaline taxa to freshwater species with low morphological diversity alongside a decrease in endemism. These results demonstrate the importance of the Devonian biotic crisis in reshaping Paleozoic ecosystems.
Systematic Parasitology, 1997
African Invertebrates, 2009
A new assemblage of arthropod cuticles from Upper Silurian rocks in Shropshire, England, includes... more A new assemblage of arthropod cuticles from Upper Silurian rocks in Shropshire, England, includes at least two centipedes and a trigonotarbid arachnid. This unequivocal terrestrial fauna from the Silurian constitutes the earliest direct record of land animals. The presence of predatory arthropods suggests that complex terrestrial ecosystems were in place by the late Silurian (414>< 10 years before present) and that the animal invasion of the land occurred earlier than was previously thought.
Palaios, Jul 1, 2012
Short chains of discoidal, rarely spheroidal, structures, recovered by acid maceration of Lower D... more Short chains of discoidal, rarely spheroidal, structures, recovered by acid maceration of Lower Devonian (Lochkovian) siltstones from the Welsh Borderland are interpreted as coprolites because they comprise comminuted or homogenized tissues. They are placed in a new species of the ichnogenus Lancifaex. Tissues include the smooth and banded tubes of Nematasketum, a close ally of Prototaxites, and rarer cuticles of Nematothallus and Cosmochlaina. All these taxa have been assigned to an extinct class, ...
Journal of the American Society …, Jan 1, 2010
Http Dx Doi Org 10 1080 14772019 2015 1018969, Mar 24, 2015
Journal of Paleontology, 2015