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.
59
datasets available to search
ShareScore release 0.9.0
Dataset results
59 results for “crocodilian”
Phylogenetic and Spatial Distribution of Evolutionary Isolation and Threat in Turtles and Crocodilians (Non-Avian Archosauromorphs)
Open the record for dataset details and reuse information.
Data from: The sex determination pattern in crocodilians: a systematic review after three decades of research
1. Sex in crocodilians is not determined by chromosomes, but by egg incubation temperature, where different temperatures produce different clutch sex ratios. Two patterns have been proposed to describe these changes in sex ratios: a 100% female proportion at low and high temperatures with male predominance at intermediate ones (FMF) or a simpler pattern with a single female to male transition (FM). Over the last three decades, researchers have provided empirical information to support either of these two patterns in different species; however, no consensus has been reached partly because data has not been analyzed as a whole. 2. Here, we aimed at gathering the existing data on these patterns to provide models of temperature-driven sex-determination in those crocodilians studied so far. 3. A preliminary literature search allowed us to integrate a glossary of terms related with the phenomenon under study. With this, we created search queries that were entered into Web of Knowledge, Scopus, Scielo and Science Direct. Studies that reported results on the sexual identity of cocodrilian hatlings obtained from constant-temperature incubation treatments were considered. Using statistical models varying in their underlying assumptions, we evaluated which sex-determination pattern was best supported for the studied crocodilians and constructed species-specific and latitud-specific models. 4. Based on the 9030 sexed hatchlings studied throughout 30 studies, we show that the evidence supports a shared FMF pattern in all the crocodilian species thus far studied. We find that such pattern changes both at the species and population levels, but not at higher taxonomical ones. We provide single-species models of the FMF pattern, along with their variation at different latitudes. 5. These results suggest a lability of the FMF crocodilian sex determination pattern, a key feature under the present climate change scenario.
The impact of molecular data on the phylogenetic position of the putative oldest crown crocodilian and the age of the clade
The use of molecular data for living groups is vital for interpreting fossils, especially when morphology-only analyses retrieve problematic phylogenies for living forms. These topological discrepancies impact on the inferred phylogenetic position of many fossil taxa. In Crocodylia, morphology-based phylogenetic inferences differ fundamentally in placing <i>Gavialis</i> basal to all other living forms, whereas molecular data consistently unite it with crocodylids. The Cenomanian <i>Portugalosuchus azenhae </i>was recently described as the oldest crown crocodilian, with affinities to <i>Gavialis</i>, based on morphology-only analyses, thus representing a potentially important new molecular clock calibration. Here we performed analyses incorporating DNA data into these morphological datasets, using scaffold and supermatrix (total evidence) approaches, in order to evaluate the position of basal crocodylians including <i>Portugalosuchus</i>. Our analyses incorporating DNA data robustly recovered <i>Portugalosuchus</i> outside Crocodylia (as well as thoracosaurs, planocraniids and <i>Borealosuchus</i> spp.), questioning the status of <i>Portugalosuchus</i> a crown crocodilian and any future use as a node calibration in molecular clock studies. Finally, we discuss how, with the increasing size of phylogenomic datasets, the molecular scaffold might be an efficient (though imperfect) approximation of more rigorous but demanding supermatrix analyses.
Data from: Spatial release from masking in crocodilians
<p>Dataset, codes, videos, and audio signals used in the study "Spatial release from masking in crocodilians". All supplementary figures are also available.</p>
Data from: The sex determination pattern in crocodilians: a systematic review after three decades of research
Open the record for dataset details and reuse information.
Data from: Diverging trends in erythrocyte size elucidate cardiovascular evolution in stem dinosaurs and crocodilians
Open the record for dataset details and reuse information.
The impact of molecular data on the phylogenetic position of the putative oldest crown crocodilian and the age of the clade
Open the record for dataset details and reuse information.
Data from: Ecological and evolutionary significance of a lack of capacity for extended developmental arrest in crocodilian eggs
Hypoxia within the oviducts maintains embryonic arrest in turtles at the pre-ovipositional stage, which expands the timeframe over which nesting can occur without compromising embryo survival. The arrest can be extended post-oviposition through incubation of eggs in hypoxia. We determined whether crocodilian embryos have this same capacity. We also tested whether increased oxygen availability during incubation alters hatching success. We incubated freshly-laid saltwater crocodile (Crocodylus porosus) eggs (N = 83) at 32°C in one of five treatments; control (normoxia; 21% O2), 3-day and 6-day hypoxia (1% O2), or 3-day and 6-day hyperoxia (42% O2). Incubation (~82 days) was then completed in normoxia. There was a significant effect of treatment on survival of embryos through to hatching (p < 0.001). The hypoxic treatments resulted in almost no hatching (6.7% and 0% survival for the 3- and 6- day treatments respectively), while the hyperoxic and control treatments resulted in normal to high hatching success (86.6%, 100% and 64.2% for the control, 3- and 6- day hyperoxic treatments respectively). Unlike turtles, hypoxic incubation of crocodile eggs failed to delay development. Our results provide the first experimental evidence that, unlike turtles, crocodiles do not exhibit embryonic arrest when incubated under hypoxic conditions immediately following oviposition. An absence of embryonic arrest is of ecological and evolutionary significance, as it implies that crocodilians lack an ability to avoid adverse environmental conditions through delayed nesting and that, unlike turtles, embryonic arrest may not be a potential explanation for the lack of viviparity in the order Crocodylia.
FIGURE 1 in Redescription and molecular characterisation of Dujardinascaris madagascariensis and a note on D. dujardini (Nematoda: Heterocheilidae), parasites of Crocodylus niloticus, with a key to Dujardinascaris spp. in crocodilians
FIGURE 1. Line drawings of Dujardinascaris madagascariensis from Crocodylus niloticus (Turkana, Kenya). A, Anterior end of female (lateral view). B, Sublateral cephalic lip with teeth. C, Details of vulva. D, Egg. E, Tail of female (dorsal view). F, Reconstruction of posterior end of male based on SEM micrograph (lateroventral view).
FIGURE 2 in Redescription and molecular characterisation of Dujardinascaris madagascariensis and a note on D. dujardini (Nematoda: Heterocheilidae), parasites of Crocodylus niloticus, with a key to Dujardinascaris spp. in crocodilians
FIGURE 2. Line drawings of Dujardinascaris madagascariensis (A, B) and D. dujardini (C, D) from Crocodylus niloticus (Turkana, Kenya). A, Entire male (lateral view). B, Position of spiculae and their relative length in an entire male (lateral view). C, Entire male (lateral view). D, Position of spiculae and their relative length an entire male (lateral view).
FIGURE 5 in Redescription and molecular characterisation of Dujardinascaris madagascariensis and a note on D. dujardini (Nematoda: Heterocheilidae), parasites of Crocodylus niloticus, with a key to Dujardinascaris spp. in crocodilians
FIGURE 5. Reproduced line drawings of Dujardinascaris gubernacula. A, E–H, and K based on Sprent et al. (1998); B, C, I, J, L–N, and P–R based on Sprent (1977); O based on Travassos (1933); J and L marked with asterisk based on our material. A, D. petterae. B, D. woodlandi. C, D. puylaerti. D, D. westonae. E, D. philippinensis. F, D. gedoelsti. G, D. blairii. H, D. harrisae. I, D. mawsonae. J, D. madagascariensis. K, D. angusae. L, D. dujardini. M, D. taylorae. N, D. chabaudi. O, D. paulista. P, D. longispicula. Q, D. helicina. R, D. waltoni.
FIGURE 3 in Redescription and molecular characterisation of Dujardinascaris madagascariensis and a note on D. dujardini (Nematoda: Heterocheilidae), parasites of Crocodylus niloticus, with a key to Dujardinascaris spp. in crocodilians
FIGURE 3. SEM micrographs of Dujardinascaris madagascariensis from Crocodylus niloticus (Turkana, Kenya). A, Cephalic end (apical view). B, Cephalic end (ventral view). C, Detail of interlocking processes. D, Detail of vulva (ventral view). E, Female caudal region (lateral view). F, Male caudal region (ventral view). G, Detail of male tail and cloacal region with papillae (indicated by arrows), asterisk indicates phasmid. H, Detail of papilla on upper cloacal lip. I, Detail of paracloacal papilla. J, Detail of phasmid.
FIGURE 4 in Redescription and molecular characterisation of Dujardinascaris madagascariensis and a note on D. dujardini (Nematoda: Heterocheilidae), parasites of Crocodylus niloticus, with a key to Dujardinascaris spp. in crocodilians
FIGURE 4. Phylogenetic position of Dujardinascaris madagascariensis in maximum likelihood (ML) tree inferred from the partial sequences (629 bp) of the 18S rDNA gene. The species Camallanus cotti was used as outgroup. The numbers above the branches indicate bootstrap values for ML resulting from 500 replicates. Only values exceeding 50 are shown.
Videos from: Spatial release from masking in crocodilians
<p>Video footages of playback experiments performed in experiment 1 (Pantanal, Brazil), in experiment 2 (Crocoparc zoo, Morocco) and in Experiment 3 (laboratory).</p>
Fig. 4 in Evidence of venom factor-like in crocodilians
Fig. 4 Densitree plot of VF-like and C3 complement. Based on analysis of database sequences of 20 species and 3712 topolo- gies. A total of 26,995 trees were drawn, shown in green. The root channel is shown in black. Every node in the phylogeny with dot shape has posterior probability higher than 0,8
Fig. 3 in Evidence of venom factor-like in crocodilians
Fig. 3 Phylogenetic tree of C3 complement. Database sequences by Bayesian inference. Posterior probabilities are greater than 9 unless indicated otherwise. The bottom bar shows the time scale divergence time in MY
Fig. 2 in Evidence of venom factor-like in crocodilians
Fig. 2 Phylogenetic tree of VF-like. Database sequences by Bayesian inference. Posterior probabilities are greater than 9 unless indicated otherwise. The bottom bar shows the time scale in MY
Fig. 1 in Evidence of venom factor-like in crocodilians
Fig. 1 Phylogenetic tree of VF-like. Including our obtained sequences from C. latirostris and sequences from GenBank (A. sinensis and A. mississippiensis), using P. gutturalis as outgroup. Posterior probabili-
Figure 1 in Egg predation and vertebrates associated with wild crocodilian nests in Mexico determined using camera-traps
Figure 1. Geographical location of the study areas and photographic records of eggs predation. Procyon lotor (a, e, f), Didelphis virginiana (b), Cuniculus paca (c), Nasua narica (d, g), and Caracara cheriway (h).
Figure 2 in Egg predation and vertebrates associated with wild crocodilian nests in Mexico determined using camera-traps
Figure 2. Non-linear regression models: (a)- Predator species increase with the number of vertebrates recorded in the areas of study. (b)- The number of nests lost decreases as crocodilian size increases.
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.