Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
10
datasets available to search
ShareScore release 0.9.0
Dataset results
10 results for “Stem-gnathostomes”
Figure 3 in Exploring phylogenetic relationships of Pteraspidiformes heterostracans (stem-gnathostomes) using continuous and discrete characters
Figure 3. Cartoons of selected characters and character states. Numbers signify characters, bracketed numbers represent character states e.g. 1(0), where 1 is the characters and (0) is the character state.
Figure 6. Most parsimonious result from a in Exploring phylogenetic relationships of Pteraspidiformes heterostracans (stem-gnathostomes) using continuous and discrete characters
Figure 6. Most parsimonious result from a phylogenetic analysis of discrete (1—64) and discretized continuous characters identified through gap coding (88—100). A, strict consensus of 30 most parsimonious trees with equally weighted characters (tree length 346). B, most parsimonious solution with implied weighted characters (k = 3) (tree length 27.86). Psammosteidae taxa in bold (for which quantitative characters have been treated as inapplicable, i.e. non-homologous).
Figure 2 in Exploring phylogenetic relationships of Pteraspidiformes heterostracans (stem-gnathostomes) using continuous and discrete characters
Figure 2. Reconstruction of a hypothetical Pteraspidiformes (adapted from Blieck 1984). A, dorsal and ventral view of Pteraspidiformes headshield with plates labelled. B, D, E, measurements used in phylogenetic analysis. C, dorsal headshield sensory canals. Anatomical abbreviations: SOC, supraorbital canal; OrbC, orbital canal; PinC, pineal canal; LDC, lateral dorsal canal; MDC, medial dorsal canal; TC, transverse commissures; MTC, median transverse commissures. Measurement abbreviations: DSL, dorsal shield length; DSW, dorsal shield width, not including the cornual plate width; DPL, dorsal plate length; DPW, dorsal plate width; RPL, rostral plate length; RPW, rostral plate width; PPL, pineal plate length; PPW, pineal plate width; BPL, brachial plate length; BOL, branchial opening distance from anterior of dorsal plate; CPL, cornual plate length; OrbPL, orbital plate length; OrbPAPL, orbital plate anterior process length; OrbPMPL, orbital plate medial process length; OrbPPPL, orbital plate posterior process length; Orb—Orb, orbital opening to orbital opening length; DSBW, dorsal spine base width; DSBL, dorsal spine base length; DPEB, dorsal plate embayment; DPEL, distance to beginning of embayment from anterior end of dorsal plate; DPEW, dorsal plate embayment narrowest width.
Figure 1. Previous Pteraspidiformes phylogenies. A in Exploring phylogenetic relationships of Pteraspidiformes heterostracans (stem-gnathostomes) using continuous and discrete characters
Figure 1. Previous Pteraspidiformes phylogenies. A, Blieck's (1984) Pteraspidiformes phylogeny for all the then-known taxa. B, Janvier's (1996) phylogeny for the major clades of Pteraspidiformes. C, Ilyes & Elliott's (1994) phylogeny for the Western USA taxa. D, Perǹegre's (2002) phylogeny to determine the position of Doryaspis. E, Perǹegre & Goujet's (2007) phylogeny to determine the position of Gigantaspis. F, Perǹegre & Elliott's (2008) most recent Pteraspidiformes phylogeny with the identification of major families. The Psammosteidae are highlighted when included in an analysis.
Figure 7. Pteraspidiformes phylogeny with genera plotted against their stratigraphical occurrences. A in Exploring phylogenetic relationships of Pteraspidiformes heterostracans (stem-gnathostomes) using continuous and discrete characters
Figure 7. Pteraspidiformes phylogeny with genera plotted against their stratigraphical occurrences. A, discrete and continuous character analysis with implied weighting (k = 3). B, discretized analysis with implied weighting (k = 3). Colours relate to palaeobiogeographical provinces.
Figure 4. Results from the phylogenetic analysis using discrete data only. A in Exploring phylogenetic relationships of Pteraspidiformes heterostracans (stem-gnathostomes) using continuous and discrete characters
Figure 4. Results from the phylogenetic analysis using discrete data only. A, strict consensus of 275 most parsimonious trees with equal character weights; length 276 steps, consistency index (CI) = 0.35, retention index (RI) = 0.59, and rescaled consistency index (RC) = 0.22. B, strict consensus of four most parsimonious trees with implied character weighting (k = 3) (tree length 23.11). Psammosteidae taxa in bold.
Figure 5 in Exploring phylogenetic relationships of Pteraspidiformes heterostracans (stem-gnathostomes) using continuous and discrete characters
Figure 5. Phylogenetic results from data sets containing discrete (1—64) and continuous (66, 68, 70, 72, 77, 80, 82, 86) characters. A, most parsimonious tree with equally weighted characters (tree length 319.36). B, most parsimonious tree with implied weighting (k = 3) (tree length 26.53). Psammosteidae taxa in bold (for which quantitative characters have been treated as inapplicable, i.e. nonhomologous).
Functional assessment of morphological homoplasy in stem-gnathostomes
<p>The Osteostraci and Galeaspida are stem gnathostomes, occupying a key phylogenetic position for resolving the nature of the jawless ancestor from which jawed vertebrates evolved more than 400 million years ago. Both groups are characterized by the presence of rigid headshields that share a number of common morphological traits, in some cases hindering the resolution of their interrelationships and the exact nature of their affinities with jawed vertebrates. Here, we explore the morphological and functional diversity of osteostracan and galeaspid headshields using an innovative approach that combines geometric morphometrics and computational fluid dynamics, thereby constraining the underlying factors that promoted the evolution of their similar morphologies and informing on the ecological scenario under which jawed vertebrates emerged. Phylomorphospace, Mantel analysis and Stayton metrics demonstrate a high degree of homoplasy. Computational fluid dynamics reveals similar hydrodynamic performance among morphologically convergent species, indicating the independent acquisition of the same morphofunctional traits and, potentially, equivalent lifestyles. This confirms that a number of the characters typically used to infer the evolutionary relationships among galeaspids, osteostracans and jawed vertebrates are convergent in nature, potentially obscuring understanding of the assembly of the gnathostome bodyplan. Ultimately, our results reveal that while the jawless relatives of the earliest jawed vertebrates were ecologically diverse, widespread convergence on the same hydrodynamic adaptations suggests they had reached the limits of their potential ecological diversity – overcome by jawed vertebrates and their later innovations.</p>
Functional assessment of morphological homoplasy in stem-gnathostomes
Open the record for dataset details and reuse information.
Data for: A phylogeny for Heterostraci (stem-gnathostomes)
Open the record for dataset details and reuse information.
ScienceDex guides
Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.