The dipnoan buccal pump reconstructed in 3D and implications for air breathing in Devonian lungfishes

Paleobiology ◽  
2016 ◽  
Vol 42 (2) ◽  
pp. 289-304 ◽  
Author(s):  
A. M. Clement ◽  
J. A. Long ◽  
P. Tafforeau ◽  
P. E. Ahlberg
Keyword(s):  
Fresh Water ◽  
Three Dimensional ◽  
Spatial Relationship ◽  
Lung Ventilation ◽  
Environmental Context ◽  
Late Devonian ◽  
Pump Mode ◽  
Air Breathing ◽  
Marine Habitats ◽  
Synchrotron Tomography

AbstractLungfishes are known for, and indeed take their name from, their bimodal respiratory abilities. All three extant genera can use their lungs to extract oxygen from the atmosphere, although their reliance upon this capability differs among taxa. Lungs are considered primitive for the Osteichthyes, however the distinctive buccal pump mode of air gulping exhibited by extant lungfishes appears to be a specialization. It is associated with a number of derived skeletal characters (cranial ribs, long parasphenoid stalk, midline gap between palatal tooth plates) that first appeared during the Devonian. These have been described individually, but in no Devonian lungfish has their three-dimensional (3D) spatial relationship been reconstructed and analyzed. Here we present the 3D morphology of Rhinodipterus, a Mid-Late Devonian lungfish from Australia and Europe, based on synchrotron tomography and conventional microtomography scans.Unlike less crownward contemporaneous lungfishes such as Griphognathus and Chirodipterus, Rhinodipterus has a full set of skeletal buccal pump components that can be directly compared to those of extant lungfishes, suggesting that it made more extensive use of air breathing than other Gogo or Bergisch Gladbach genera. This is interesting in relation to the environmental context as Gogo and Bergisch Gladbach are both marine, contrasting with the frequently hypoxic tropical to subtropical fresh water environments inhabited by modern lungfishes. The evolution of buccal pump-supported lung ventilation was evidently not necessarily associated with a transition to non-marine habitats.

scholarly journals Air-breathing adaptation in a marine Devonian lungfish

2010 ◽  
Vol 6 (4) ◽  
pp. 509-512 ◽  
Author(s):  
Alice M. Clement ◽  
John A. Long
Keyword(s):  
Middle Devonian ◽  
Late Devonian ◽  
Tidal Zone ◽  
Air Breathing ◽  
Aerial Respiration ◽  
Oxygen Levels ◽  
Marine Habitats ◽  
Metabolic Costs ◽  
Freshwater Habitats ◽  
Marine Realm

Recent discoveries of tetrapod trackways in 395 Myr old tidal zone deposits of Poland (Niedźwiedzki et al . 2010 Nature 463 , 43–48 ( doi:10.1038/nature.08623 )) indicate that vertebrates had already ventured out of the water and might already have developed some air-breathing capacity by the Middle Devonian. Air-breathing in lungfishes is not considered to be a shared specialization with tetrapods, but evolved independently. Air-breathing in lungfishes has been postulated as starting in Middle Devonian times ( ca 385 Ma) in freshwater habitats, based on a set of skeletal characters involved in air-breathing in extant lungfishes. New discoveries described herein of the lungfish Rhinodipterus from marine limestones of Australia identifies the node in dipnoan phylogeny where air-breathing begins, and confirms that lungfishes living in marine habitats had also developed specializations to breathe air by the start of the Late Devonian ( ca 375 Ma). While invasion of freshwater habitats from the marine realm was previously suggested to be the prime cause of aerial respiration developing in lungfishes, we believe that global decline in oxygen levels during the Middle Devonian combined with higher metabolic costs is a more likely driver of air-breathing ability, which developed in both marine and freshwater lungfishes and tetrapodomorph fishes such as Gogonasus .

Shifting perspectives: method, media and the complex image

1998 ◽  
Vol 10 (1-3) ◽  
pp. 100-108 ◽  
Author(s):  
Alicia Colson ◽  
Ross Parry
Keyword(s):  
Image Processing ◽  
Three Dimensional ◽  
Geographical Location ◽  
Spatial Relationship ◽  
Two Dimensional ◽  
Dimensional Approach ◽  
Complex Image ◽  
Cultural Resonance

This article argues that the analysis of a threedimensional image demanded a three-dimensional approach. The authors realise that discussions of images and image processing inveterately conceptualise representation as being flat, static, and finite. The authors recognise the need for a fresh acuteness to three-dimensionality as a meaningful – although problematic – element of visual sources. Two dramatically different examples are used to expose the shortcomings of an ingrained two-dimensional approach and to facilitate a demonstration of how modern (digital) techniques could sanction new historical/anthropological perspectives on subjects that have become all too familiar. Each example could not be more different in their temporal and geographical location, their cultural resonance, and their historiography. However, in both these visual spectacles meaning is polysemic. It is dependent upon the viewer's spatial relationship to the artifice as well as the spirito-intellectual viewer within the community. The authors postulate that the multi- faceted and multi-layered arrangement of meaning in a complex image could be assessed by working beyond the limitations of the two-dimensional methodological paradigm and by using methods and media that accommodated this type of interconnectivity and representation.

scholarly journals Application of 3D printed model for planning the endoscopic endonasal transsphenoidal surgery

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xing Huang ◽  
Ni Fan ◽  
Hai-jun Wang ◽  
Yan Zhou ◽  
Xudong Li ◽  
...  
Keyword(s):  
3D Printing ◽  
Skull Base ◽  
Transsphenoidal Surgery ◽  
Three Dimensional ◽  
Spatial Relationship ◽  
Cranial Computed Tomography ◽  
Imaging Data ◽  
Endoscopic Endonasal ◽  
Endoscopic Endonasal Transsphenoidal Surgery

AbstractThe application of 3D printing in planning endoscopic endonasal transsphenoidal surgery is illustrated based on the analysis of patients with intracranial skull base diseases who received treatment in our department. Cranial computed tomography/magnetic resonance imaging data are attained preoperatively, and three-dimensional reconstruction is performed using MIMICS (Materialise, Leuven, Belgium). Models of intracranial skull base diseases are printed using a 3D printer before surgery. The models clearly demonstrate the morphologies of the intracranial skull base diseases and the spatial relationship with adjacent large vessels and bones. The printing time of each model is 12.52–15.32 h, and the cost ranges from 900 to 1500 RMB. The operative approach was planned in vitro, and patients recovered postoperatively well without severe complications or death. In a questionnaire about the application of 3D printing, experienced neurosurgeons achieved scores of 7.8–8.8 out of 10, while unexperienced neurosurgeons achieved scores of 9.2–9.8. Resection of intracranial skull base lesions is demonstrated to be well assisted by 3D printing technique, which has great potential in disclosing adjacent anatomical relationships and providing the required help to clinical doctors in preoperative planning.

scholarly journals Diversity and distribution patterns of the Oligocene and Miocene decapod crustaceans (Crustacea: Malacostraca) of the Western and Central Paratethys

2016 ◽  
Vol 67 (5) ◽  
pp. 471-494 ◽  
Author(s):  
Matúš Hyžný
Keyword(s):  
Spatial Scales ◽  
Three Dimensional ◽  
Decapod Crustacean ◽  
Distribution Patterns ◽  
Mediterranean Area ◽  
Homogeneous Distribution ◽  
Decapod Crustaceans ◽  
Central Paratethys ◽  
The North ◽  
Marine Habitats

AbstractDecapod associations have been significant components of marine habitats throughout the Cenozoic when the major diversification of the group occurred. In this respect, the circum-Mediterranean area is of particular interest due to its complex palaeogeographic history. During the Oligo-Miocene, it was divided in two major areas, Mediterranean and Paratethys. Decapod crustaceans from the Paratethys Sea have been reported in the literature since the 19thcentury, but only recent research advances allow evaluation of the diversity and distribution patterns of the group. Altogether 176 species-level taxa have been identified from the Oligocene and Miocene of the Western and Central Paratethys. Using the three-dimensional NMDS analysis, the composition of decapod crustacean faunas of the Paratethys shows significant differences through time. The Ottnangian and Karpatian decapod associations were similar to each other both taxonomically and in the mode of preservation, and they differed taxonomically from the Badenian ones. The Early Badenian assemblages also differed taxonomically from the Late Badenian ones. The time factor, including speciation, immigration from other provinces and/or (local or global) extinction, can explain temporal differences among assemblages within the same environment. High decapod diversity during the Badenian was correlated with the presence of reefal settings. The Badenian was the time with the highest decapod diversity, which can, however, be a consequence of undersampling of other time slices. Whereas the Ottnangian and Karpatian decapod assemblages are preserved virtually exclusively in the siliciclastic “Schlier”-type facies that originated in non-reefal offshore environments, carbonate sedimentation and the presence of reefal environments during the Badenian in the Central Paratethys promoted thriving of more diverse reef-associated assemblages. In general, Paratethyan decapods exhibited homogeneous distribution during the Oligo-Miocene among the basins in the Paratethys. Based on the co-occurrence of certain decapod species, migration between the Paratethys and the North Sea during the Early Miocene probably occurred via the Rhine Graben. At larger spatial scales, our results suggest that the circum-Mediterranean marine decapod taxa migrated in an easterly direction during the Oligocene and/or Miocene, establishing present-day decapod communities in the Indo-West Pacific.

The evolution of the terrestrial vertebrates: environmental and physiological considerations

1985 ◽  
Vol 309 (1138) ◽  
pp. 289-322 ◽  
Keyword(s):  
Fresh Water ◽  
Osmotic Dehydration ◽  
The Body ◽  
Geological Evidence ◽  
Air Breathing ◽  
Marine Origin ◽  
Terrestrial Vertebrates ◽  
Terrestrial Life ◽  
Tetrapod Evolution

Physiological evidence has long been used to suggest that the gnathostomous vertebrates (those possessing jaws) were primitively fresh water. The same was also the case for the Osteichthyes (bony fish) and the Tetrapoda (Amphibia, Reptilia, Aves, Mammalia). However, the geological evidence favours a marine origin for the vertebrates as a whole, and, for the gnathostomes and the osteichthyans in particular. Some of the earliest amphibian remains may be associated with tidally influenced sediments. Furthermore, during the early part of the Devonian, fresh water chemistry may well have been different from that of today, lessening the divide between marine and non-marine environments. Urea formation via the ornithine cycle, and urea retention in the body fluids, are useful adaptations for terrestrial life. They prevent excessive water loss associated with the elimination of nitrogenous waste. These abilities may have been primitive for the gnathostomes, and were developed in the marine environment to reduce osmotic dehydration. In the .aqueous medium, gaseous exchange is effected by the gills. These organs are, on the whole, useless in air. For vertebrates, air-breathing is effected by an inflatable sac, with moist linings, and an internal location. Some form of air-breathing sac was primitive for the osteichthyans, and may have been primitive for the gnathostomes. Again, this adaptation for terrestrial life developed in response to conditions experienced in the marine, aquatic environment. A new model of tetrapod evolution is proposed in the light of the basic marine origin and character of the ancestors of the tetrapods.

Other non-marine invertebrates

1985 ◽  
Vol 309 (1138) ◽  
pp. 239-240 ◽  
Keyword(s):  
Fresh Water ◽  
Littoral Zone ◽  
Marine Invertebrates ◽  
Suspension Feeding ◽  
Larval Life ◽  
Intertidal Environment ◽  
Air Breathing ◽  
Fresh Waters ◽  
Reproductive Processes

Two classes of Mollusca have successfully emerged from the sea: the Bivalvia to fresh waters but the Gastropoda, in addition to invading the fresh water habitat, have also become fully air-breathing and live on the land. There is today a complete range from those taxa that are in every respect fully marine to those that are completely independent of the sea. The possible pathways from the sea to these environments are by surviving reduced or varying salinities, which it might be assumed occur in intertidal or estuarine conditions, or by surviving periodic and increasing exposure in air, again a condition of the intertidal environment. The prerequisite for emergence from the sea must have been the presence of food. In the initial emergence this could have been provided by detritus derived from the sea and deposited along a feature such as a storm beach. Such an environment is probably important for some Ellobiidae today. To spread onto the land and into the fresh water Mollusca, as other essentially grazing or suspension feeding animals, were presumably preceded by Bacteria or plants, or both. The initial modifications to metabolic and reproductive processes, outlined by Little (1983), may have taken place high in the littoral zone, supported by detritus and, as in the Ellobiidae, remaining dependent on the sea during larval life. The expansion and radiation of the Mollusca that has followed may have been related to the increase in habitats made available by the plants.

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