The stomach of a male sperm whale (Physeter macrocephalus) stranded near Comodoro Rivadavia, Arge... more The stomach of a male sperm whale (Physeter macrocephalus) stranded near Comodoro Rivadavia, Argentina, on 21 March 1986, contained 247 cephalopod beaks (128 upper and 119 lower). The lower beaks were identified, their rostral lengths were measured and used to estimate the mantle lengths and wet weight of the representatives of each cephalopod taxon. Fifteen species from nine families were represented. The most numerous species, in order of decreasing abundance, were the large cranchiidMesonychoteuthis hamiltoni (32.8% of total numbers),Mastigoteuthis sp. A (16.0%), andKondakovia longimana andHistioteuthis atlantica (both 13.5%). Almost 85% of the estimated total weight was contributed by two species,Mesonychoteuthis hamiltoni (61.6%) andK. longimana (23.1%). The presence of beaks fromK. longimana, Alluroteuthis antarcticus andM. hamiltoni, which are all thought to be restricted to the Antarctic, suggests that the whale had migrated North prior to stranding.
Outline-based morphometric methods have been more-or-less restricted to the consideration of clos... more Outline-based morphometric methods have been more-or-less restricted to the consideration of closed curves and plagued by problems related to the maintenance of close biological correspondence across all forms within a sample. Methods developed herein generalize and extend the eigenshape method of outline analysis along the following lines: (1) consideration of open curves, (2) improvement of interobject correspondence via incorporation of information provided by landmarks, and (3) extension to the analysis of three-dimensional (open and closed) curves. In addition, techniques for using eigenshape results to create models of shape variation and for more consistently assessing the digital resolution necessary to represent an object are discussed and illustrated. These improvements are then placed in context via discussions of previous attempts to extend morphometric outline analysis methods, the relation between landmark and outline-based morphometric methods, the use of morphometric analyses to test biological hypotheses, and the nature of morphometric shape spaces (with special reference to studies of morphological disparity).
a new method of subdivided relative warp analysis (described herein) performs very well at recogn... more a new method of subdivided relative warp analysis (described herein) performs very well at recognizing simulated morphological character states and recovering a simulated morphological phylogenetic hierarchy. Based on these results it is concluded that the potential of morphometric data analysis methods (especially relative warp-based methods) to contribute to phylogenetic-systematic investigations should be explored further.
Abstract.-The depositional history of Upper Miocene through Recent sediments from DSDP Site 214 (... more Abstract.-The depositional history of Upper Miocene through Recent sediments from DSDP Site 214 (Ninetyeast Ridge, Indian Ocean) is reexamined. Samples of the Globorotalia tumida planktic foraminiferal lineage, originally obtained from these sediments by Malmgren et al. (1983), ...
The Systematics Association Special Volume Series Series Editor Alan Warren Department of Zoology... more The Systematics Association Special Volume Series Series Editor Alan Warren Department of Zoology, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK. The Systematics Association provides a forum for discussing systematic problems and integrating new ...
Abstract.-It is now widely recognized that a large number of Cretaceous planktic foraminiferal sp... more Abstract.-It is now widely recognized that a large number of Cretaceous planktic foraminiferal species are commonly found associated with fully Danian faunas in many K/T boundary sections and deep-sea cores. This "Cretaceous" fauna has traditionally been regarded as ...
Geological Society, London, Special …, Jan 1, 1998
Abstract: The Phanerozoic history of life has been interrupted by at least 17 different stage-lev... more Abstract: The Phanerozoic history of life has been interrupted by at least 17 different stage-level episodes of elevated extinction intensity. These range from major turnovers that affect-ed the majority of the Earth's extant biota (eg the Tatarian, Ashgill, and Maastrichtian events) to ...
... and Cretaceous-Tertiary Boundary Foraminiferal Turnover and Environmental Changes at Agost, S... more ... and Cretaceous-Tertiary Boundary Foraminiferal Turnover and Environmental Changes at Agost, Spain Alfonso Pardo, Nieves Ortiz, and ... 14: The Cretaceous-Tertiary Boundary in the Nanxiong Basin (Continental Facies, Southeast China) Johannes Stets, Abdul-Rahman Ashraf ...
Quantitative analyses of global diversity in the marine fossil record over Phanerozoic time revea... more Quantitative analyses of global diversity in the marine fossil record over Phanerozoic time reveal an historically ordered pattern of sequential dominance and increasing diversity. Explanatory models applied to this empirical pattern lead to irreconcilable differences of interpretation. The issue may be resolved by determining the expected distributions and limits of temporal covariation among clades generated by a random branching process. Results also challenge the claim that asymmetries in intra-clade diversity variation provide a directional arrow for the history of life.
... One of the chapters contains a very informative account of the methodology, including the&... more ... One of the chapters contains a very informative account of the methodology, including the'pros ... Careful reading of this chapter will disclose links to the natural categorization of objects ... In many publications and summarized in his brilliant PhD thesis of 1979, Norman A. Campbell ...
The earliest Tertiary planktic foraminiferal taxonomic diversification has long been regarded as ... more The earliest Tertiary planktic foraminiferal taxonomic diversification has long been regarded as one of the best examples of adaptive radiation within the microfossil record. However, the morphologic, phylogenetic, and paleoecologic data required to validate this interpretation ...
The analysis of morphology is crucial to the study of phylogeny in many ancient and modern organi... more The analysis of morphology is crucial to the study of phylogeny in many ancient and modern organismal groups. Recently a number of arguments have been made in favor of regarding certain kinds of morphometric variables as putatively homologous characters and allowing them to participate, along with other non-morphometric variables, in parsimony-based cladistic analyses. These arguments rest on the assumptions that geometric landmarks incorporate the concept of biological homology and that partial warp and principal warp morphometric variables uniquely incorporate and operationalize the concept of spatial localization, thus providing investigators with the ability to assess patterns and directions of geometrical variation in unmeasured regions of organic forms. Literature review, coupled with empirical investigations of similarities and differences among three different morphometric data analysis methods on two different datasets suggest that there is no support for these assertions. Geometric landmarks, which form the basis for all morphometric measurements and latent shape variables, have no necessary correspondence to biological homology. Partial warp variables, coordinate-point eigenshape variables, and inter-landmark distance-based singular vector shape-change variables all express localized (= regionally-weighted) geometric deformations. However, none of these deformation patterns are localized in the sense of being truly independent from globally-distributed aspects of shape change. All three of the morphometric data analysis methods investigated are capable of inferring patterns of shape change in remote regions of the form so long as a spatially adequate array of landmarks is used as the basis for the shape analysis. Based on these results it is concluded that: (1) all types of morphometric procedures are potentially useful in phylogenetic inference to the extent that they are able to summarize patterns of biotic shape change within the Euclidean space of the original measurements; (2) morphometric interpretations are strengthened by using alternative analytic approaches to probe the geometric system in a hypothetico-deductive manner and achieve a robust and consistent interpretation of underlying differences among operational taxonomic units (OTU s); and (3) while deformationbased morphometric variables can be used to analyze the distribution of organic shapes in a variety of measurement and latent variable spaces, they represent abstract investigative tools that are tied irreducibly to particular samples and data. Such variables can be used to study morphological characters, refine character and character state definitions, and aid in the assignment of character states to OTU s. However, they are not characters themselves and may not be suitable for phylogenetic analyses directly. In addition, a new morphometric data analysis technique coordinate-point eigenshape analysis is described and its use illustrated.
ABSTRACT See Plates 20 and 21 In historical sciences such as palaeontology, cause and effect must... more ABSTRACT See Plates 20 and 21 In historical sciences such as palaeontology, cause and effect must be established by documenting multiple associations of proposed causes and observed effects in the correct logical sequence. Employing this approach, the ...
(1982) for the benthonic foraminiferan Afrobolivina afar. G. plesiotumida is recognizable on the ... more (1982) for the benthonic foraminiferan Afrobolivina afar. G. plesiotumida is recognizable on the basis of independent data as a species distinct from G. tumida, its descendant. Evolutionary change rate during the evolution of G. tumida from G. plesiotumida is shown to be faster than ...
The stomach of a male sperm whale (Physeter macrocephalus) stranded near Comodoro Rivadavia, Arge... more The stomach of a male sperm whale (Physeter macrocephalus) stranded near Comodoro Rivadavia, Argentina, on 21 March 1986, contained 247 cephalopod beaks (128 upper and 119 lower). The lower beaks were identified, their rostral lengths were measured and used to estimate the mantle lengths and wet weight of the representatives of each cephalopod taxon. Fifteen species from nine families were represented. The most numerous species, in order of decreasing abundance, were the large cranchiidMesonychoteuthis hamiltoni (32.8% of total numbers),Mastigoteuthis sp. A (16.0%), andKondakovia longimana andHistioteuthis atlantica (both 13.5%). Almost 85% of the estimated total weight was contributed by two species,Mesonychoteuthis hamiltoni (61.6%) andK. longimana (23.1%). The presence of beaks fromK. longimana, Alluroteuthis antarcticus andM. hamiltoni, which are all thought to be restricted to the Antarctic, suggests that the whale had migrated North prior to stranding.
Outline-based morphometric methods have been more-or-less restricted to the consideration of clos... more Outline-based morphometric methods have been more-or-less restricted to the consideration of closed curves and plagued by problems related to the maintenance of close biological correspondence across all forms within a sample. Methods developed herein generalize and extend the eigenshape method of outline analysis along the following lines: (1) consideration of open curves, (2) improvement of interobject correspondence via incorporation of information provided by landmarks, and (3) extension to the analysis of three-dimensional (open and closed) curves. In addition, techniques for using eigenshape results to create models of shape variation and for more consistently assessing the digital resolution necessary to represent an object are discussed and illustrated. These improvements are then placed in context via discussions of previous attempts to extend morphometric outline analysis methods, the relation between landmark and outline-based morphometric methods, the use of morphometric analyses to test biological hypotheses, and the nature of morphometric shape spaces (with special reference to studies of morphological disparity).
a new method of subdivided relative warp analysis (described herein) performs very well at recogn... more a new method of subdivided relative warp analysis (described herein) performs very well at recognizing simulated morphological character states and recovering a simulated morphological phylogenetic hierarchy. Based on these results it is concluded that the potential of morphometric data analysis methods (especially relative warp-based methods) to contribute to phylogenetic-systematic investigations should be explored further.
Abstract.-The depositional history of Upper Miocene through Recent sediments from DSDP Site 214 (... more Abstract.-The depositional history of Upper Miocene through Recent sediments from DSDP Site 214 (Ninetyeast Ridge, Indian Ocean) is reexamined. Samples of the Globorotalia tumida planktic foraminiferal lineage, originally obtained from these sediments by Malmgren et al. (1983), ...
The Systematics Association Special Volume Series Series Editor Alan Warren Department of Zoology... more The Systematics Association Special Volume Series Series Editor Alan Warren Department of Zoology, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK. The Systematics Association provides a forum for discussing systematic problems and integrating new ...
Abstract.-It is now widely recognized that a large number of Cretaceous planktic foraminiferal sp... more Abstract.-It is now widely recognized that a large number of Cretaceous planktic foraminiferal species are commonly found associated with fully Danian faunas in many K/T boundary sections and deep-sea cores. This "Cretaceous" fauna has traditionally been regarded as ...
Geological Society, London, Special …, Jan 1, 1998
Abstract: The Phanerozoic history of life has been interrupted by at least 17 different stage-lev... more Abstract: The Phanerozoic history of life has been interrupted by at least 17 different stage-level episodes of elevated extinction intensity. These range from major turnovers that affect-ed the majority of the Earth's extant biota (eg the Tatarian, Ashgill, and Maastrichtian events) to ...
... and Cretaceous-Tertiary Boundary Foraminiferal Turnover and Environmental Changes at Agost, S... more ... and Cretaceous-Tertiary Boundary Foraminiferal Turnover and Environmental Changes at Agost, Spain Alfonso Pardo, Nieves Ortiz, and ... 14: The Cretaceous-Tertiary Boundary in the Nanxiong Basin (Continental Facies, Southeast China) Johannes Stets, Abdul-Rahman Ashraf ...
Quantitative analyses of global diversity in the marine fossil record over Phanerozoic time revea... more Quantitative analyses of global diversity in the marine fossil record over Phanerozoic time reveal an historically ordered pattern of sequential dominance and increasing diversity. Explanatory models applied to this empirical pattern lead to irreconcilable differences of interpretation. The issue may be resolved by determining the expected distributions and limits of temporal covariation among clades generated by a random branching process. Results also challenge the claim that asymmetries in intra-clade diversity variation provide a directional arrow for the history of life.
... One of the chapters contains a very informative account of the methodology, including the&... more ... One of the chapters contains a very informative account of the methodology, including the'pros ... Careful reading of this chapter will disclose links to the natural categorization of objects ... In many publications and summarized in his brilliant PhD thesis of 1979, Norman A. Campbell ...
The earliest Tertiary planktic foraminiferal taxonomic diversification has long been regarded as ... more The earliest Tertiary planktic foraminiferal taxonomic diversification has long been regarded as one of the best examples of adaptive radiation within the microfossil record. However, the morphologic, phylogenetic, and paleoecologic data required to validate this interpretation ...
The analysis of morphology is crucial to the study of phylogeny in many ancient and modern organi... more The analysis of morphology is crucial to the study of phylogeny in many ancient and modern organismal groups. Recently a number of arguments have been made in favor of regarding certain kinds of morphometric variables as putatively homologous characters and allowing them to participate, along with other non-morphometric variables, in parsimony-based cladistic analyses. These arguments rest on the assumptions that geometric landmarks incorporate the concept of biological homology and that partial warp and principal warp morphometric variables uniquely incorporate and operationalize the concept of spatial localization, thus providing investigators with the ability to assess patterns and directions of geometrical variation in unmeasured regions of organic forms. Literature review, coupled with empirical investigations of similarities and differences among three different morphometric data analysis methods on two different datasets suggest that there is no support for these assertions. Geometric landmarks, which form the basis for all morphometric measurements and latent shape variables, have no necessary correspondence to biological homology. Partial warp variables, coordinate-point eigenshape variables, and inter-landmark distance-based singular vector shape-change variables all express localized (= regionally-weighted) geometric deformations. However, none of these deformation patterns are localized in the sense of being truly independent from globally-distributed aspects of shape change. All three of the morphometric data analysis methods investigated are capable of inferring patterns of shape change in remote regions of the form so long as a spatially adequate array of landmarks is used as the basis for the shape analysis. Based on these results it is concluded that: (1) all types of morphometric procedures are potentially useful in phylogenetic inference to the extent that they are able to summarize patterns of biotic shape change within the Euclidean space of the original measurements; (2) morphometric interpretations are strengthened by using alternative analytic approaches to probe the geometric system in a hypothetico-deductive manner and achieve a robust and consistent interpretation of underlying differences among operational taxonomic units (OTU s); and (3) while deformationbased morphometric variables can be used to analyze the distribution of organic shapes in a variety of measurement and latent variable spaces, they represent abstract investigative tools that are tied irreducibly to particular samples and data. Such variables can be used to study morphological characters, refine character and character state definitions, and aid in the assignment of character states to OTU s. However, they are not characters themselves and may not be suitable for phylogenetic analyses directly. In addition, a new morphometric data analysis technique coordinate-point eigenshape analysis is described and its use illustrated.
ABSTRACT See Plates 20 and 21 In historical sciences such as palaeontology, cause and effect must... more ABSTRACT See Plates 20 and 21 In historical sciences such as palaeontology, cause and effect must be established by documenting multiple associations of proposed causes and observed effects in the correct logical sequence. Employing this approach, the ...
(1982) for the benthonic foraminiferan Afrobolivina afar. G. plesiotumida is recognizable on the ... more (1982) for the benthonic foraminiferan Afrobolivina afar. G. plesiotumida is recognizable on the basis of independent data as a species distinct from G. tumida, its descendant. Evolutionary change rate during the evolution of G. tumida from G. plesiotumida is shown to be faster than ...
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