Hans-Peter Schultze | University of Kansas (original) (raw)
Papers by Hans-Peter Schultze
Environmental Biology of Fishes, Sep 1, 1991
Recent radiologic imaging techniques (CT[Computed Tomography] and MRI[Magnetic Resonance Imaging]... more Recent radiologic imaging techniques (CT[Computed Tomography] and MRI[Magnetic Resonance Imaging]) were used to investigate the cranial anatomy of the coelacanth Latimeria chalumnae. The non-invasive CT and MRI techniques were performed successfully on a 1.45 m female specimen. This specimen had been frozen a year earlier for future research; the CT was conducted on the frozen animal, whereas the MRI method
Herpetological Osteopathology, 2011
Fossil Record, 2016
Scales of a new species of Teleosteomorpha from the continental Aptian of the south of South Amer... more Scales of a new species of Teleosteomorpha from the continental Aptian of the south of South America are studied. These neopterygians are from the La Cantera Formation in central Argentina, and were previously identified as Pholidophoriformes. They present ganoid scales; most of them are rhombic with well-developed peg-and-socket articulations and possessing a smooth surface. They have a straight posterior margin, but occasionally, some scales of the flank have a sinuous posterior margin with one or two serrations. The shape of the scales varies along the body from large, rectangular and deeper than long scales behind the head to the preanal region to smaller and rhomboidal scales in the caudal region. There are a few horizontal rows along the flank and about 32 lateral line scales. Thick, round ganoid scales are present in the prepelvic region close to the ventral margin. The round and rhombic scales present growth lines, which form concentric ridges on the external side. A characteristic row of deep scales forms the dorsal margin on each side of the body; a row of median ridge scales is not present. This is a unique feature of the studied fishes. Scutes covered with unornamented ganoine precede the pelvic, dorsal, and anal fins, as well as the dorsal and ventral margins of the caudal fin. The posterior margin of the dorsal lobe of the caudal fin is formed by a single line of scales, which continues and covers the base of the first principal caudal ray. Histological studies reveal a lepisosteoid-scale type with multiple ganoine layers, lack of dentine, and the presence of canaliculi of Williamson. The macro-and micromorphology of the scales shows features that are found in other teleosteomorphs, but also in other neopterygians.
FIG. 5. — Cladograms generated by PAUP 4.01b10 for Windows (Swofford 2002), data (see Table 2) co... more FIG. 5. — Cladograms generated by PAUP 4.01b10 for Windows (Swofford 2002), data (see Table 2) compiled with NEXUS Data Editor (Page 1999), using 68 unordered, equal weight characters, heuristic search, starting trees obtained by stepwise addition with random addition sequence, tree-bisection-reconnection branch swapping; trees generated using Treeview X (Page 1996): A-C, using the original 17 taxa, characters of Donoghue et al. (2000) recoded (see Appendices 1; 2); Consistency index (CI) = 0.5971, Homoplasy index (HI) = 0.4029, and Retention index (RI) = 0.6940 (see Appendix 4 for CI, HI and RI values for the single characters); 27 shortest trees of equal length = 139 steps, with numbered nodes (cf. apomorphy lists, Appendix 3) for the trees illustrated and 50% majority rule bootstrap values given in italics (under node number) at nodes supported by the bootstrap analyses; A, ACCTRAN character-state optimisation (accelerated appearance of character states), tree 6 of 27 equal lengt...
Journal of Vertebrate Paleontology, 2000
A possible representative of the early vertebrates is reported for the first time from a graptoli... more A possible representative of the early vertebrates is reported for the first time from a graptolite-dated Lower Ordovician (lower Arenig) siliciclastic sequence in the Eastern Cordillera of southern Bolivia. The specimen is preserved as a natural mold of an exoskeleton plate ...
Journal of Vertebrate Paleontology, 1986
Journal of Morphology, 1986
Dipnoans are osteichthyans, and are the sister group of crossopterygians (actinistians, onychodon... more Dipnoans are osteichthyans, and are the sister group of crossopterygians (actinistians, onychodontiforms, porolepiforms, osteolepiforms, and including tetrapods). They share with crossopterygians the following derived features: anocleithrum, connection between the preopercular and infraorbital sensory lines, true enamel on teeth, cosmine, sclerotic ring with more than four plates, submandibular series, archipterygium, and process of endochondral bone formation. These features characterize the sarcopterygians (crossopterygians and dipnoans), whereas the intracranial joint, double-headed hyomandibula, and three extrascapulae are synapomorphies of crossopterygians. Rhipidistians (onychodontiforms, porolepiforms, osteolepiforms, and including tetrapods) are characterized by two synapomorphies, the presence of an extratemporal and narrow submandibular bone($. Plicidentine, four infradentaries, three coronoids, and a fenestra ventro-lateralis are synapomorphies of porolepiforms, osteolepiforms, and tetrapods. The tetrapods are most closely related to panderichthyid osteolepiforms (with which they share labyrinthodont plicidentine, three pairs of median skull roof bones, flat skull with high dorsally situated orbits, and marginal position of external naris). The common ancestor of dipnoans and tetrapods is also the common ancestor of crossopterygians (including tetrapods) and dipnoans; in other words, the hypothetical common ancestor of all sarcopterygians. The dipnoans are not the closest sister group of tetrapods, independently if living forms only are considered, or fossil forms included.
Journal of Morphology, 1992
The ontogenetic development of caudal vertebrae and associated skeletal elements of salmonids pro... more The ontogenetic development of caudal vertebrae and associated skeletal elements of salmonids provides information about sequence of ossification and origin of bones that can be considered as a model for other teleosts. The ossification of elements forming the caudal skeleton follows the same sequence, independent of size and age at first appearance. Dermal bones like principal caudal rays ossify earlier than chondral bones; among dermal bones, the middle principal caudal rays ossify before the ventrd and dorsal ones. Among chondral bones, the ventral hypural 1 and parhypural ossify first, followed by hypural 2 and by the ventral spine of preural centrum 2 . The ossification of the dorsal chondral elements starts later than that of ventral ones. Three elements participate in the formation of a caudal vertebra: paired basidorsal and basiventral arcocentra, chordacentrum, and autocentrum; appearance of cartilaginous arcocentra precedes that of the mineralized basiventral chordacentrum, and that of the perichordal ossification of the autocentrum. Each ural centrum is mainly formed by arcocentra and chordacentrum.
Journal of Morphology, 1990
The formation of the unpaired structure ventral to the basibranchial region, the so-called urohya... more The formation of the unpaired structure ventral to the basibranchial region, the so-called urohyal, differs within osteichthyans. A cartilaginous preformed, unpaired "urohyal" is present in sarcopterygians. A three-tendon ossification is present in Polypterus. An %rohyal" or urohyal is absent in both Amia and Lepisosteus. The urohyal formed as an unpaired ossification of the tendon of the sternohyoideus muscle is a feature of teleosts. A new structure, the parurohyal, arises as a double 1 H.-P. SCHULTZE tant fishes were taken with a Stereoscan Philipps 501 at the University of Kansas; those of acid-prepared bones of the Jurassic teleost Leptolepis coryphaenoides with a Stereoscan Mark IIA (Cambridge) a t the Universitiit Gottingen.
Journal of Morphology, 1991
The palatoquadrate and associated dermal bones have significant evolutionary transformations amon... more The palatoquadrate and associated dermal bones have significant evolutionary transformations among teleostomes and provide numerous features that characterize teleostomian subgroups. The palatoquadrate forms the upper part of the mandibular arch and is present as a single cartilaginous element in the early ontogeny of teleostomes, except for some advanced teleosts such as siluroids where it is divided into pars autopalatina and pars pterygoquadrata. During ontogeny, the palatoquadrate may ossify as a unit, with a pars autopalatina (absent in Acanthodii), pars quadrata, and pars metapterygoidea in teleostomes (e.g., primitive acanthodians and actinopterygians, onychodonts, and rhipidistians). However, the palatoquadrate may remain cartilaginous (e.g., chondrosteans) or it may ossify as separate elements (e.g., autopalatine, metapterygoid, and quadrate) as occurs in advanced acanthodians, Polypterus and advanced actinopterygians, and advanced actinistians. From the single-unit pattern, separate autopalatine, metapterygoid, and quadrate evolve in parallel in the three teleostomian subgroups. Therefore, it is necessary to distinguish between actinopterygian and actinistian autopalatines and among acanthodian, actinopterygian, and actinistian metapterygoids and quadrates. A palatoquadrate fused with the neurocranium occurs in parallel in dipnoans.
Journal of Morphology, 2001
A vertebral column consisting of a persistent notochord and ossified arcocentra is the primitive ... more A vertebral column consisting of a persistent notochord and ossified arcocentra is the primitive condition for Gnathostomata; it still persists in primitive actinopterygians and sarcopterygians. Advanced actinopterygians and sarcopterygians develop numerous types of centra that include, among others, the presence of holocentrum, chordacentrum, and autocentrum. The chordacentrum, a mineralization or calcification of the fibrous sheath of the notochord, is only found in actinopterygians, whereas an autocentrum is a synapomorphy of teleosts above †Leptolepis coryphaenoides. The chordacentrum, formed by migration of cartilaginous cells from the arches into the fibrous sheath of the notochord and usually covered by a thin calcification, is a unique feature of chondrichthyans. The actinopterygian chordacentrum and the chondrichthyan chordacentrum are not homologous. The postcaudal cartilaginous centrum is only known in postcaudal vertebrae of living dipnoans. The holocentrum is present in certain fossil dipnoans and actinopterygians, where it has been independently acquired. It is formed by proliferation of cartilage cells around the elastica externa of the notochord. These cells later ossify, forming a compact centrum. A vertebral column formed by a persistent notochord without vertebral centra is the primitive pattern for all vertebrates. The formation of centra, which is not homologous among vertebrate groups, is acquired independently in some lineages of placoderms, most advanced actinopterygians, and some dipnoans and rhipidistians. Several series of structures are associated with the vertebral column such as the supraneurals, interhaemals, radials, and ribs. In living dipnoans median neural spine, 'supraneural', and dorsal radial result from growth and distal differentiation of one median cartilage into two or three median bones during ontogeny. The median neural spine articulates with the neural arch and fuses with it in the caudal vertebrae early in ontogeny. Two bones differentiate in the anterior abdominal vertebrae, i.e., the proximal neural spine and the distal 'supraneural.' Three bones differentiate in front of the dorsal fin, i.e., the proximal neural spine, the middle 'supraneural,' and the distal radial; the same pattern is observed in front of the anal fin (the proximal haemal spine, the middle interhaemal, and the distal radial). Considering that the three dorsal (and also the three ventral) bones originate from growth of only one cartilage, they cannot be serial homologs of the neural spines, or 'supraneural.' They are linear homologs of the median neural cartilage in living dipnoans. The development of these elements differs within osteichthyans from sarcopterygians to actinopterygians, in which the neural spine originates as a continuation of the basidorsal arcualia and in which the supraneural and radial originate from independent cartilages that appear at different times during early ontogeny. The ribs of living dipnoans are unique in that they are not articulated with parapophyses, like in primitive fossil dipnoans, but a remnant of the ventral arcuale surrounded by a small arcocentrum remains at its base. A true caudal fin is absent in living dipnoans. The postcaudal cartilages extend to the caudal tip of the body separating dorsal and ventral rays (or the camptotrichia). Actinotrichia are present in young dipnoans. They are also known in extant actinistians and actinopterygians. They probably represent the primitive state for teleostomes. In contrast, the camptotrichia are unique for extant dipnoans (and probably Carboniferous and younger dipnoans). Lepidotrichia apparently developed many times among osteichthyans.
Journal of Molecular Evolution, 1992
Meyer and Wilson's (1990) 12S rRNA phylogeny unites lungfish and tetrapods to the exclusi... more Meyer and Wilson's (1990) 12S rRNA phylogeny unites lungfish and tetrapods to the exclusion of the coelacanth. These workers also provide a list of morphological features shared in common between modern lungfish and tetrapods, and they conclude that these traits were probably present in their last common ancestor. However, the exquisite fossil records of the abundant extinct lungfishes and rhipidistians show that at least 13 out of Meyer and Wilson's 14 supposed ancestral traits were not present in the last common ancestor of lungfishes and tetrapods. Using extant taxa to infer ancestral morphologies is fraught with difficulties; just like molecular sequences, ancestral character states of morphological traits may be severely overprinted by subsequent modifications. Modern lungfish are air-breathing nonmarine forms, yet their Devonian forebears were marine fish that did not breathe air. Fossils dating from the time of origin of tetrapods in the Devonian offer the only hope of understanding the morphological innovations that led to tetrapods; morphological analysis of the "living fossils," the coelacanth and lungfish, only lends confusion.
Fossil Record – Mitteilungen aus dem Museum für Naturkunde, 2007
Three Late Jurassic actinopterygian species are commonly placed in the genus Eurycormus: E. egert... more Three Late Jurassic actinopterygian species are commonly placed in the genus Eurycormus: E. egertoni, E. grandis and E. speciosus. A detailed comparison supports an earlier assignment to two different genera, Eurycormus Wagner, 1863 (speciosus) and Eurypoma Huxley, 1866 (E. egertoni and E. grande). Systematically, the two genera are only distantly related; Eurycormus belongs to the Teleosteomorpha, whereas Eurypoma is a halecomorph closely related to or a member of the Caturoidea within the Amiiformes.
Mitteilungen aus dem Museum für Naturkunde in Berlin. Geowissenschaftliche Reihe, 2004
Mitteilungen aus dem Museum für Naturkunde in Berlin - Geowissenschaftliche Reihe, 2005
Fossil Record, 1999
The late Late Jurassic fishes collected by the Tendaguru expeditions (1909)(1910)(1911)(1912)(191... more The late Late Jurassic fishes collected by the Tendaguru expeditions (1909)(1910)(1911)(1912)(1913) are represented only by a shark tooth and various specimens of the neopterygian Lepidotes . The Lepidotes is a new species characterized by a combination of features such as the presence of scattered tubercles in cranial bones of adults, smooth ganoid scales, two suborbital bones, one row of infraorbital bones, non-tritoral teeth, hyomandibula with an anteriorly expanded membranous outgrowth, two extrascapular bones, two postcleithra, and the absence of fringing fulcra on all fins.
Fossil Record, 2012
Fossil Record 15 (1) 2012, 5 -25
Canadian Journal of Earth Sciences, 1987
Quebecius quebecensis (Whiteaves 1889) is a porolepiform crossopterygian related to Glyptolepis. ... more Quebecius quebecensis (Whiteaves 1889) is a porolepiform crossopterygian related to Glyptolepis. A large nariodal, a large tabular, a separate intertemporal, and a large fused nasosupraorbital are features of Quebecius that characterize it as a porolepiform. The ...
Canadian Journal of Earth Sciences, 2002
... The fin-spines of Mesacanthus are grooved, with thickened ribs along the leading edge and fin... more ... The fin-spines of Mesacanthus are grooved, with thickened ribs along the leading edge and fine striations posteriorly along the side of each spine. ... Mesacanthus, in constrast, has longitudinally elongated, enlarged cranial plates. ... A new Late Devonian acanthodian fish from Mt. ...
Environmental Biology of Fishes, Sep 1, 1991
Recent radiologic imaging techniques (CT[Computed Tomography] and MRI[Magnetic Resonance Imaging]... more Recent radiologic imaging techniques (CT[Computed Tomography] and MRI[Magnetic Resonance Imaging]) were used to investigate the cranial anatomy of the coelacanth Latimeria chalumnae. The non-invasive CT and MRI techniques were performed successfully on a 1.45 m female specimen. This specimen had been frozen a year earlier for future research; the CT was conducted on the frozen animal, whereas the MRI method
Herpetological Osteopathology, 2011
Fossil Record, 2016
Scales of a new species of Teleosteomorpha from the continental Aptian of the south of South Amer... more Scales of a new species of Teleosteomorpha from the continental Aptian of the south of South America are studied. These neopterygians are from the La Cantera Formation in central Argentina, and were previously identified as Pholidophoriformes. They present ganoid scales; most of them are rhombic with well-developed peg-and-socket articulations and possessing a smooth surface. They have a straight posterior margin, but occasionally, some scales of the flank have a sinuous posterior margin with one or two serrations. The shape of the scales varies along the body from large, rectangular and deeper than long scales behind the head to the preanal region to smaller and rhomboidal scales in the caudal region. There are a few horizontal rows along the flank and about 32 lateral line scales. Thick, round ganoid scales are present in the prepelvic region close to the ventral margin. The round and rhombic scales present growth lines, which form concentric ridges on the external side. A characteristic row of deep scales forms the dorsal margin on each side of the body; a row of median ridge scales is not present. This is a unique feature of the studied fishes. Scutes covered with unornamented ganoine precede the pelvic, dorsal, and anal fins, as well as the dorsal and ventral margins of the caudal fin. The posterior margin of the dorsal lobe of the caudal fin is formed by a single line of scales, which continues and covers the base of the first principal caudal ray. Histological studies reveal a lepisosteoid-scale type with multiple ganoine layers, lack of dentine, and the presence of canaliculi of Williamson. The macro-and micromorphology of the scales shows features that are found in other teleosteomorphs, but also in other neopterygians.
FIG. 5. — Cladograms generated by PAUP 4.01b10 for Windows (Swofford 2002), data (see Table 2) co... more FIG. 5. — Cladograms generated by PAUP 4.01b10 for Windows (Swofford 2002), data (see Table 2) compiled with NEXUS Data Editor (Page 1999), using 68 unordered, equal weight characters, heuristic search, starting trees obtained by stepwise addition with random addition sequence, tree-bisection-reconnection branch swapping; trees generated using Treeview X (Page 1996): A-C, using the original 17 taxa, characters of Donoghue et al. (2000) recoded (see Appendices 1; 2); Consistency index (CI) = 0.5971, Homoplasy index (HI) = 0.4029, and Retention index (RI) = 0.6940 (see Appendix 4 for CI, HI and RI values for the single characters); 27 shortest trees of equal length = 139 steps, with numbered nodes (cf. apomorphy lists, Appendix 3) for the trees illustrated and 50% majority rule bootstrap values given in italics (under node number) at nodes supported by the bootstrap analyses; A, ACCTRAN character-state optimisation (accelerated appearance of character states), tree 6 of 27 equal lengt...
Journal of Vertebrate Paleontology, 2000
A possible representative of the early vertebrates is reported for the first time from a graptoli... more A possible representative of the early vertebrates is reported for the first time from a graptolite-dated Lower Ordovician (lower Arenig) siliciclastic sequence in the Eastern Cordillera of southern Bolivia. The specimen is preserved as a natural mold of an exoskeleton plate ...
Journal of Vertebrate Paleontology, 1986
Journal of Morphology, 1986
Dipnoans are osteichthyans, and are the sister group of crossopterygians (actinistians, onychodon... more Dipnoans are osteichthyans, and are the sister group of crossopterygians (actinistians, onychodontiforms, porolepiforms, osteolepiforms, and including tetrapods). They share with crossopterygians the following derived features: anocleithrum, connection between the preopercular and infraorbital sensory lines, true enamel on teeth, cosmine, sclerotic ring with more than four plates, submandibular series, archipterygium, and process of endochondral bone formation. These features characterize the sarcopterygians (crossopterygians and dipnoans), whereas the intracranial joint, double-headed hyomandibula, and three extrascapulae are synapomorphies of crossopterygians. Rhipidistians (onychodontiforms, porolepiforms, osteolepiforms, and including tetrapods) are characterized by two synapomorphies, the presence of an extratemporal and narrow submandibular bone($. Plicidentine, four infradentaries, three coronoids, and a fenestra ventro-lateralis are synapomorphies of porolepiforms, osteolepiforms, and tetrapods. The tetrapods are most closely related to panderichthyid osteolepiforms (with which they share labyrinthodont plicidentine, three pairs of median skull roof bones, flat skull with high dorsally situated orbits, and marginal position of external naris). The common ancestor of dipnoans and tetrapods is also the common ancestor of crossopterygians (including tetrapods) and dipnoans; in other words, the hypothetical common ancestor of all sarcopterygians. The dipnoans are not the closest sister group of tetrapods, independently if living forms only are considered, or fossil forms included.
Journal of Morphology, 1992
The ontogenetic development of caudal vertebrae and associated skeletal elements of salmonids pro... more The ontogenetic development of caudal vertebrae and associated skeletal elements of salmonids provides information about sequence of ossification and origin of bones that can be considered as a model for other teleosts. The ossification of elements forming the caudal skeleton follows the same sequence, independent of size and age at first appearance. Dermal bones like principal caudal rays ossify earlier than chondral bones; among dermal bones, the middle principal caudal rays ossify before the ventrd and dorsal ones. Among chondral bones, the ventral hypural 1 and parhypural ossify first, followed by hypural 2 and by the ventral spine of preural centrum 2 . The ossification of the dorsal chondral elements starts later than that of ventral ones. Three elements participate in the formation of a caudal vertebra: paired basidorsal and basiventral arcocentra, chordacentrum, and autocentrum; appearance of cartilaginous arcocentra precedes that of the mineralized basiventral chordacentrum, and that of the perichordal ossification of the autocentrum. Each ural centrum is mainly formed by arcocentra and chordacentrum.
Journal of Morphology, 1990
The formation of the unpaired structure ventral to the basibranchial region, the so-called urohya... more The formation of the unpaired structure ventral to the basibranchial region, the so-called urohyal, differs within osteichthyans. A cartilaginous preformed, unpaired "urohyal" is present in sarcopterygians. A three-tendon ossification is present in Polypterus. An %rohyal" or urohyal is absent in both Amia and Lepisosteus. The urohyal formed as an unpaired ossification of the tendon of the sternohyoideus muscle is a feature of teleosts. A new structure, the parurohyal, arises as a double 1 H.-P. SCHULTZE tant fishes were taken with a Stereoscan Philipps 501 at the University of Kansas; those of acid-prepared bones of the Jurassic teleost Leptolepis coryphaenoides with a Stereoscan Mark IIA (Cambridge) a t the Universitiit Gottingen.
Journal of Morphology, 1991
The palatoquadrate and associated dermal bones have significant evolutionary transformations amon... more The palatoquadrate and associated dermal bones have significant evolutionary transformations among teleostomes and provide numerous features that characterize teleostomian subgroups. The palatoquadrate forms the upper part of the mandibular arch and is present as a single cartilaginous element in the early ontogeny of teleostomes, except for some advanced teleosts such as siluroids where it is divided into pars autopalatina and pars pterygoquadrata. During ontogeny, the palatoquadrate may ossify as a unit, with a pars autopalatina (absent in Acanthodii), pars quadrata, and pars metapterygoidea in teleostomes (e.g., primitive acanthodians and actinopterygians, onychodonts, and rhipidistians). However, the palatoquadrate may remain cartilaginous (e.g., chondrosteans) or it may ossify as separate elements (e.g., autopalatine, metapterygoid, and quadrate) as occurs in advanced acanthodians, Polypterus and advanced actinopterygians, and advanced actinistians. From the single-unit pattern, separate autopalatine, metapterygoid, and quadrate evolve in parallel in the three teleostomian subgroups. Therefore, it is necessary to distinguish between actinopterygian and actinistian autopalatines and among acanthodian, actinopterygian, and actinistian metapterygoids and quadrates. A palatoquadrate fused with the neurocranium occurs in parallel in dipnoans.
Journal of Morphology, 2001
A vertebral column consisting of a persistent notochord and ossified arcocentra is the primitive ... more A vertebral column consisting of a persistent notochord and ossified arcocentra is the primitive condition for Gnathostomata; it still persists in primitive actinopterygians and sarcopterygians. Advanced actinopterygians and sarcopterygians develop numerous types of centra that include, among others, the presence of holocentrum, chordacentrum, and autocentrum. The chordacentrum, a mineralization or calcification of the fibrous sheath of the notochord, is only found in actinopterygians, whereas an autocentrum is a synapomorphy of teleosts above †Leptolepis coryphaenoides. The chordacentrum, formed by migration of cartilaginous cells from the arches into the fibrous sheath of the notochord and usually covered by a thin calcification, is a unique feature of chondrichthyans. The actinopterygian chordacentrum and the chondrichthyan chordacentrum are not homologous. The postcaudal cartilaginous centrum is only known in postcaudal vertebrae of living dipnoans. The holocentrum is present in certain fossil dipnoans and actinopterygians, where it has been independently acquired. It is formed by proliferation of cartilage cells around the elastica externa of the notochord. These cells later ossify, forming a compact centrum. A vertebral column formed by a persistent notochord without vertebral centra is the primitive pattern for all vertebrates. The formation of centra, which is not homologous among vertebrate groups, is acquired independently in some lineages of placoderms, most advanced actinopterygians, and some dipnoans and rhipidistians. Several series of structures are associated with the vertebral column such as the supraneurals, interhaemals, radials, and ribs. In living dipnoans median neural spine, 'supraneural', and dorsal radial result from growth and distal differentiation of one median cartilage into two or three median bones during ontogeny. The median neural spine articulates with the neural arch and fuses with it in the caudal vertebrae early in ontogeny. Two bones differentiate in the anterior abdominal vertebrae, i.e., the proximal neural spine and the distal 'supraneural.' Three bones differentiate in front of the dorsal fin, i.e., the proximal neural spine, the middle 'supraneural,' and the distal radial; the same pattern is observed in front of the anal fin (the proximal haemal spine, the middle interhaemal, and the distal radial). Considering that the three dorsal (and also the three ventral) bones originate from growth of only one cartilage, they cannot be serial homologs of the neural spines, or 'supraneural.' They are linear homologs of the median neural cartilage in living dipnoans. The development of these elements differs within osteichthyans from sarcopterygians to actinopterygians, in which the neural spine originates as a continuation of the basidorsal arcualia and in which the supraneural and radial originate from independent cartilages that appear at different times during early ontogeny. The ribs of living dipnoans are unique in that they are not articulated with parapophyses, like in primitive fossil dipnoans, but a remnant of the ventral arcuale surrounded by a small arcocentrum remains at its base. A true caudal fin is absent in living dipnoans. The postcaudal cartilages extend to the caudal tip of the body separating dorsal and ventral rays (or the camptotrichia). Actinotrichia are present in young dipnoans. They are also known in extant actinistians and actinopterygians. They probably represent the primitive state for teleostomes. In contrast, the camptotrichia are unique for extant dipnoans (and probably Carboniferous and younger dipnoans). Lepidotrichia apparently developed many times among osteichthyans.
Journal of Molecular Evolution, 1992
Meyer and Wilson's (1990) 12S rRNA phylogeny unites lungfish and tetrapods to the exclusi... more Meyer and Wilson's (1990) 12S rRNA phylogeny unites lungfish and tetrapods to the exclusion of the coelacanth. These workers also provide a list of morphological features shared in common between modern lungfish and tetrapods, and they conclude that these traits were probably present in their last common ancestor. However, the exquisite fossil records of the abundant extinct lungfishes and rhipidistians show that at least 13 out of Meyer and Wilson's 14 supposed ancestral traits were not present in the last common ancestor of lungfishes and tetrapods. Using extant taxa to infer ancestral morphologies is fraught with difficulties; just like molecular sequences, ancestral character states of morphological traits may be severely overprinted by subsequent modifications. Modern lungfish are air-breathing nonmarine forms, yet their Devonian forebears were marine fish that did not breathe air. Fossils dating from the time of origin of tetrapods in the Devonian offer the only hope of understanding the morphological innovations that led to tetrapods; morphological analysis of the "living fossils," the coelacanth and lungfish, only lends confusion.
Fossil Record – Mitteilungen aus dem Museum für Naturkunde, 2007
Three Late Jurassic actinopterygian species are commonly placed in the genus Eurycormus: E. egert... more Three Late Jurassic actinopterygian species are commonly placed in the genus Eurycormus: E. egertoni, E. grandis and E. speciosus. A detailed comparison supports an earlier assignment to two different genera, Eurycormus Wagner, 1863 (speciosus) and Eurypoma Huxley, 1866 (E. egertoni and E. grande). Systematically, the two genera are only distantly related; Eurycormus belongs to the Teleosteomorpha, whereas Eurypoma is a halecomorph closely related to or a member of the Caturoidea within the Amiiformes.
Mitteilungen aus dem Museum für Naturkunde in Berlin. Geowissenschaftliche Reihe, 2004
Mitteilungen aus dem Museum für Naturkunde in Berlin - Geowissenschaftliche Reihe, 2005
Fossil Record, 1999
The late Late Jurassic fishes collected by the Tendaguru expeditions (1909)(1910)(1911)(1912)(191... more The late Late Jurassic fishes collected by the Tendaguru expeditions (1909)(1910)(1911)(1912)(1913) are represented only by a shark tooth and various specimens of the neopterygian Lepidotes . The Lepidotes is a new species characterized by a combination of features such as the presence of scattered tubercles in cranial bones of adults, smooth ganoid scales, two suborbital bones, one row of infraorbital bones, non-tritoral teeth, hyomandibula with an anteriorly expanded membranous outgrowth, two extrascapular bones, two postcleithra, and the absence of fringing fulcra on all fins.
Fossil Record, 2012
Fossil Record 15 (1) 2012, 5 -25
Canadian Journal of Earth Sciences, 1987
Quebecius quebecensis (Whiteaves 1889) is a porolepiform crossopterygian related to Glyptolepis. ... more Quebecius quebecensis (Whiteaves 1889) is a porolepiform crossopterygian related to Glyptolepis. A large nariodal, a large tabular, a separate intertemporal, and a large fused nasosupraorbital are features of Quebecius that characterize it as a porolepiform. The ...
Canadian Journal of Earth Sciences, 2002
... The fin-spines of Mesacanthus are grooved, with thickened ribs along the leading edge and fin... more ... The fin-spines of Mesacanthus are grooved, with thickened ribs along the leading edge and fine striations posteriorly along the side of each spine. ... Mesacanthus, in constrast, has longitudinally elongated, enlarged cranial plates. ... A new Late Devonian acanthodian fish from Mt. ...
The origin and the phylogenetic interrelationships of teleosts have been controversial subjects e... more The origin and the phylogenetic interrelationships of teleosts have been controversial subjects ever since Greenwood, P. H., Rosen, D. E., Weitzman, S. H. and Myers, G. S. in 1966 presented a revision of teleost phylogeny. Different taxa (Amia, Lepisosteus, Amia + Lepisosteus, †Pycnodontiformes, †Dapedium, †Pachycormiformes, and others) have been proposed as the sister group of teleosts. Tremendous advances have occurred in our knowledge of Neopterygii, basal to teleosts, and in their major component the teleosts over the past 40 years. Many new key fossils have been studied, and many extant teleost clades have been traced back to the Jurassic in detailed studies by Gloria Arratia in 1987, 1996, and 2000. In addition to new fossils, a large number of new morphological and molecular characters have been incorporated in recent phylogenetic analyses, adding to our arsenal of approaches. This book gives a modern view of these approaches. It includes a compilation of synapomorphies of numerous teleostean taxa with a new proposal of their classification, a proposal that pycnodonts are the fossil sister group of teleosts, a phylogeny based on mitochondrial genome sequences, separate analyses of basal teleostean taxa (Osteoglossomorpha, Clupeiformes, Gonorynchiformes, Cypriniformes, Characiformes, Siluriformes, Salmoniformes, Esociformes) and the euteleostean Aulopiformes, karyological studies of Cyprinodontidae, and morphological analyses of the posterior part of the neurocranium. A biography of Gloria Arratia is also presented.
The book represents contributions to the symposium “Origin and phylogenetic interrelationships of teleosts” sponsored by the American Society of Ichthyologists and Herpetologists (ASIH) and organized by the three editors of this volume and held at the Society’s annual meeting in St. Louis, Missouri, on 14 July 2007. At the same meeting, Gloria Arratia was honored with the Robert H. Gibbs, Jr. Memorial Award, 2007, for her outstanding contributions to systematic ichthyology. The volume presents the current state of phylogenetic knowledge of the origin of teleosts and the interrelationships of teleost groups, both key issues in fish systematics, based on both morphological (of extant and fossil taxa) and molecular evidence. The many contributors to the volume present and evaluate progress in studying both characters and taxa and in establishing databases (morphological and molecular) that will be of use in future.