Search bioRxivSearch

bioRxiv · 10.1101/505495

Crustaceans as hosts of parasites throughout the Phanerozoic

Abstract

The fossil record of crustaceans as hosts of parasites has yielded three confirmed associations: epicaridean isopod-induced swellings on Jurassic–Recent decapod crustaceans, feminization of Cretaceous and Miocene male crabs possibly caused by rhizocephalan barnacles, and presumed pentastomids on/in Silurian ostracods. Cestode platyhelminth hooks and swellings by entoniscid isopods may be recognized in the future. Relative to 2014, we report an increase of 41% to 124 fossil decapod species with epicaridean-induced swellings in the branchial chamber (ichnotaxon Kanthyloma crusta). Furthermore, using a Late Jurassic (Tithonian) decapod assemblage from Austria, we find (1) no correlation between genus abundance and prevalence of K. crusta, (2) host preference for some galatheoid taxa (as for a mid-Cretaceous assemblage from Spain), and (3) a larger median size of parasitized versus non-parasitized specimens for two selected species. The latter result may be caused by infestation throughout ontogeny rather than exclusively in juveniles and/or possible selection for the larger sex.View Full Text

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Klompmaker, A. A., Robins, C. M., Portell, R. W., De Angeli, A.. 2018-12-31. Crustaceans as hosts of parasites throughout the Phanerozoic. https://doi.org/10.1101/505495

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Constraining Palaeogeography and Palaeotides for the Cambrian using cnidarian medusae

The ocean tides influence key Earth system processes at a range of spatial and temporal scales. It is known that the geometry of ocean basins is the leading controller of tidal energetics, so well-constrained palaeogeographic reconstructions and tidal properties for Earths past are imperative when investigating other Earth system processes. Here, we present a novel way to constrain both deep-time tidal model results and reconstructions, by combining palaeoecology with sedimentology. We compare new palaeo-tidal model simulations for the Cambrian period, significant for the early origin and radiation of major animal fauna, to tidal proxies. One of the most abundant soft-bodied organisms preserved during this time are cnidarian medusae (jellyfish). A total of 17 cnidarian medusae localities were obtained through the literature, which had an adequate global distribution and occurred at regular intervals throughout the period of study. In some locations there were also estimates of palaeo-tidal range. Our results show a good agreement between the simulations and proxy data. In the few locations where there is disagreement, it is proposed that the palaeogeographic reconstructions are missing details, e.g., island chains, and our results allow for the palaeogeographic reconstructions to be improved. The proxy method presented is promising and can be applied to other time-periods with different marine fossils, particularly at evolutionary and extinction periods where the marginal marine environment is of importance.

paleontology

Bayesian Tip-dated Phylogenetics: Topological Effects, Stratigraphic Fit and the Early Evolution of Mammals

ABSTRACTThe incorporation of stratigraphic data into phylogenetic analysis has a long history of debate, but is not currently standard practice for palaeontologists. Bayesian tip-dating (or morphological clock) phylogenetic methods have returned these arguments to the spotlight, but how tip-dating affects the recovery of evolutionary relationships has yet to be fully explored. Here we show, through analysis of several datasets with multiple phylogenetic methods, that topologies produced by tip-dating are outliers when compared to topologies produced by parsimony and undated Bayesian methods, which retrieve broadly similar trees. Unsurprisingly, trees recovered by tip-dating have better fit to stratigraphy than trees recovered by other methods, due to trees with better stratigraphic fit being assigned a higher prior probability. Differences in stratigraphic fit and tree topology between tip-dating and other methods appear to be concentrated in parts of the tree with weaker character signal and a stronger influence of the prior, as shown by successive deletion of the most incomplete taxa from a sauropod dataset. Tip-dating applied to Mesozoic mammals firmly rejects a monophyletic Allotheria, and strongly supports diphyly of haramiyidans, with the late Triassic Haramiyavia and Thomasia forming a clade with tritylodontids, which is distant from the middle Jurassic euharamiyidans. This result is not sensitive to the controversial age of the eutherian Juramaia. A Test of the age of Juramaia using a less restrictive prior reveals strong support from the data for an Early Cretaceous age. Our results suggest that tip-dating incorporates stratigraphic data in an intuitive way, with good stratigraphic fit a prior expectation that can be overturned by strong evidence from character data.View Full Text

paleontology

Earliest-known intentionally deformed human cranial fossil from Asia and the initiation of hereditary hierarchy in the early Holocene

Hereditary hierarchy is one of the major features of complex societies. Without a written record, prehistoric evidence for hereditary hierarchy is rare. Intentional cranial deformation (ICD) is a cross-generational cultural practice that embodies social identity and culture beliefs in adults through the behavior of altering infant head shape. Therefore, ICD is usually regarded as an archeological clue for the occurrence of hereditary hierarchy. With a calibrated radiocarbon age of 11245-11200 years BP, a fossil skull of an adult male displaying ICD discovered in Northeastern China is among the oldest-known ICD practices in the world. Along with the other earliest global occurrences of ICD, this discovery points to the early initiation of complex societies among the non-agricultural local societies in Northeastern Asia in the early Holocene. A population increase among previously more isolated terminal Pleistocene/early Holocene hunter-gatherer groups likely increased their interactions, possibly fueling the formation of the first complex societies.View Full Text

paleontology