Historical Zoogeography of the Eusuchian Crocodilians: A Physiological Perspective

Taplin, L. E.; Grigg, Gordon C.

doi:10.1093/icb/29.3.885

Cited by 87 publications

(71 citation statements)

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“…several North American and African forms) may be more distantly related. These interpretations support the possibility discussed by Densmore and Dessauer (1982) and Taplin and Grigg (1989) that many or all of the extant crocodylids might be derived relatively recently from marine-adapted ancestors with physiological capabilities similar to C. porosus.…”

Section: Discussionsupporting

confidence: 88%

“…The finding that C. johnstoni has much in common with C. porosus and with all the other crocodylids studied to date has interesting implications for evolutionary and zoogeographic interpretations of crocodilian history (see Taplin and Grigg 1989;Pidcock et al 1997). In particular, Willis and co-workers have published extensively in recent years on the history and systematic relationships of the numerous fossil crocodilians discovered in Australia -several of them from within the range of C. porosus and C. johnstoni in northern Australia (see Willis 1997 for review).…”

Section: Discussionmentioning

confidence: 99%

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Osmoregulatory mechanisms of the Australian freshwater crocodile, Crocodylus johnstoni , in freshwater and estuarine habitats

Taplin¹,

Grigg²,

Beard³

et al. 1999

Journal of Comparative Physiology B: Biochemical, Systemic, and

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Abstract. The estuary of the Limmen Bight River in Australia's Northern Territory is home to an unusual salt water-adapted population of the Australian `freshwater' crocodile, Crocodylus johnstoni. Crocodiles were captured from tidal reaches of the estuary ranging in salinity from 0.5-24 0 / 00 and from several permanent fresh water reaches more or less remote from saline waters. C. johnstoni is an effective osmoregulator in moderately saline waters and has osmoregulatory mechanisms very similar to its more marine-adapted relative, the estuarine crocodile Crocodylus porosus. Fasted C. johnstoni in brackish water appear to lose little sodium in cloacal urine, relying on their lingual salt glands for excretion of excess sodium chloride. The lingual glands show clear evidence of short-term and long-term acclimation to salt water. Like estuarine crocodiles, C. johnstoni drinks fresh water and will not drink sea water. Gross sodium and water fluxes in brackish water are very similar to those in other crocodilians, suggesting differences in integumental permeability are not a major influence on osmoregulatory differences between crocodilians. The data reinforce the hypothesis that crocodylids differ fundamentally from alligatorids in the structure and function of the renal-cloacal-salt gland complex and are of interest in current debate over the evolutionary and zoogeographical history of the eusuchian crocodilians.

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Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Osmoregulatory mechanisms of the Australian freshwater crocodile, Crocodylus johnstoni , in freshwater and estuarine habitats

Taplin¹,

Grigg²,

Beard³

et al. 1999

Journal of Comparative Physiology B: Biochemical, Systemic, and

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“…3) with the available information on the distribution of fossils and living crocodilians through time (32) …”

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confidence: 99%

Generic affinities among crocodilians as revealed by DNA fingerprinting with a Bkm-derived probe.

Aggarwal

Majumdar

Lang

et al. 1994

Proc. Natl. Acad. Sci. U.S.A.

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Genetic fingerprint profiles have been succesfublly used for estabishing biological relationships, in linkage analysis, and in studies ofpopulato structure but have not so far been used for ascertalning phylogenetic relationships among related groups of species and genera. This Is largely because these proffles are thought to evolve too rapidly to be informative over large time intervals. However, we show here that among the Crocodilla, whose phylogeny is a debated Issue, these profiles can provide phylogenetically useful formation.By using the probe Bkm-2(8), DNA gerprints with distinct bands distributed in the size range 0.5-23.0 kb were obtained for individuals of 18 species belonging to seven of the eight genera of crocodiflans. These genetic profiles showed hidividual-, species-, and restriction enzyme-specific patterns. In addition, string differences were observed in the copy number of Bkm-related sequences in genomes of different crocodiflan species. The qualitative data from DNA flngirpit proffles, and quantitae data on copy number variation in Bkm-related sequences, suggest that these genera belong to two distinct groups, one of which includes Aligator, Paeosuchuis, and Caiman; the other incudes Crocodylus, Osteolkemus, Tomistoma, and Gavialis. A close relationship between Tomistoma and Gabals is also suggested by these results.Crocodilians are the sole living reptilian representatives of the subclass Archosauria, a highly successful group in the Mesozoic era both in numbers and in diversity. At present, only 8 of the 124 described genera have survived and all of these belong to the same suborder, Eusuchia (1). According to most systematists, there are only 21 extant species, 11 of which belong to Crocodylus, which is by far the largest genus.The natural affinities among living crocodilians have so far been determined primarily on the basis of comparative morphology and paleontological records. However, the resolving power of these approaches has not been adequate to solve certain problematic and confusing relationships within the order Crocodilia. The commonality in life-style of many of the crocodilian taxa may have led to similar adaptative strategies-e.g., convergent skull morphology and head shape. Such convergence in characters, although considered phylogenetically important, has made interpretation of the systematic relationships in crocodilians difficult (2). This has led to the use of other approaches such as cytogenetic parameters (3, 4), analysis ofcoevolving crocodilian-parasite lineages (5), biochemical and immunological studies of proteins (6-8), and Southern blot and DNA sequence analyses of mitochondrial and nuclear ribosomal DNA (9-11) to resolve the natural affinities and evolutionary history of the living crocodilians.On the basis of the approaches described above, there is general agreement in aing Osteolaemus with Crocodylus and the caimans (Caiman, Melanosuchus, Paleosuchus) as the nearest sister taxa ofAlligator, whereas opinion is divided on the affinities of the two gha...

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“…There are two living species of Alligator -one in North America (the American alligator, Alligator mississippiensis) and another in China (the critically endangered Chinese alligator, A. sinensis). Because alligators are intolerant of salt water [43], a nonmarine dispersal corridor, such as Beringia, probably explains the presence of an otherwise North American clade in eastern Asia [44], [45], [46]. Fossil evidence puts the minimum divergence time between the two lineages in the early Miocene [47], but highlatitude dispersal routes would not have been within crocodylian thermal preferences at that time [11].…”

Section: Discussionmentioning

confidence: 99%

First FossilAlligatorfrom the Late Eocene of Nebraska and the Late Paleogene Record of Alligators in the Great Plains

Whiting

Hastings

2015

Journal of Herpetology

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Background: Discovery of Eocene non-marine vertebrates, including crocodylians, turtles, bony fishes, and mammals in Canada's High Arctic was a critical paleontological contribution of the last century because it indicated that this region of the Arctic had been mild, temperate, and ice-free during the early -middle Eocene (,53-50 Ma), despite being well above the Arctic Circle. To date, these discoveries have been restricted to Canada's easternmost Arctic -Ellesmere and Axel Heiberg Islands (Nunavut). Although temporally correlative strata crop out over 1,000 km west, on Canada's westernmost Arctic Island -Banks Island, Northwest Territories -they have been interpreted as predominantly marine. We document the first Eocene bony fish and crocodyliform fossils from Banks Island.

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Historical Zoogeography of the Eusuchian Crocodilians: A Physiological Perspective

Cited by 87 publications

References 0 publications

Osmoregulatory mechanisms of the Australian freshwater crocodile, Crocodylus johnstoni , in freshwater and estuarine habitats

Osmoregulatory mechanisms of the Australian freshwater crocodile, Crocodylus johnstoni , in freshwater and estuarine habitats

Generic affinities among crocodilians as revealed by DNA fingerprinting with a Bkm-derived probe.

First FossilAlligatorfrom the Late Eocene of Nebraska and the Late Paleogene Record of Alligators in the Great Plains

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