Skip to main content Accesibility Help
×
×
Home

IX.—The Postcranial Skeleton of Ensthenopteron foordi Whiteaves*

  • S. Mahala Andrews (a1) and T. Stanley Westoll (a2)
Synopsis

Well preserved material of the crossopterygian fish Eusthenopteron enables fresh reconstructions and interpretations of its postcranial skeleton to be given. Comparisons throughout with other bony fishes show that it may be primitive in many features. Similarities with early amphibians such as the screw-shaped glenoid, the form of the humerus (on which an attempt to restore the pectoral musculature is based), the dorsal bicipital ribs and the possibility of a sacral attachment, throw much light on the origin of the tetrapod postcranial skeleton, particularly of the cheiropterygium. A functional analysis of the skeleton of Ensthenopteron is attempted, suggesting that it resembled the pike (Esox) in its mode of life and that it may have been capable of short journeys “walking” overland. The possible selective factors stimulating the evolution of such a fish, and further evolution to the tetrapod stage are discussed.

Copyright
References
Hide All
Aldinger, H., 1931. “Über einige Besonderheiten im Schädeldach von Eusthenopteron foordi Wh.” Zentbl. Miner. Geol. Paläont., B, 300305.
Ball, H. W., Dineley, D. L. and White, E. I., 1961. “The Old Red Sandstone of Brown Clee Hill and the Adjacent Area”, Bull. Br. Mus. Nat. Hist. (Geol.), 5, 177310, pl. 33–8.
Barrell, J., 1916. “Influence of Silurian-Devonian climates on the rise of air-breathing vertebrates”, Bull. Geol. Soc. Am., 27, 387436.
Bertin, L., 1958. “Modifications des Nageoires”. In Grassé, J-P., Ed., Traite de Zoologie, 13, (I), 748782. Paris: Masson.
Bertin, L. and Arambourg, C., 1958. “Systématique des Poissons. Super-Ordre des Téléostéens”. In Grassé, J-P., Ed., Traité de Zoologie, 13 (3), 1967–1983 and 22042500. Paris: Masson.
Braus, H., 1901. “Die Muskeln und Nerven der Ceratodusflosse”. Denkschr. Med.-Naturw. Ges. Jena, 4, 137300, pl. XXI–XXIX.
Braus, H., 1906. “Die Entwicklung der Form der Extremitäten und des Extremitätenskelett”. In Hertwig, O., Ed., Handbuch d. vergl. und exp. Entwicklungslehre, 3 (2), 167338. Jena: Fischer.
Broom, R., 1913. “On the Origin of the Cheiropterygium”, Bull. Am. Mus. Nat. Hist., 32, 459464.
Bryant, W. L., 1919. “On the Structure of Eusthenopteron”, Bull. Buffalo Soc. Nat. Sci., 13, 123, pl. I-XVIII.
Carroll, R. L., 1965. “Lungfish Burrows from the Michigan Coal Basin”, Science, N.Y., 148, 963964.
Dean, B., 1906. “Notes on the Living Specimens of the Australian lungfish, Ceratodus forsteri, in the Zoological Society's collection”, Proc. Zool. Soc. Lond., 1906, 168178, pl. IX.
Denison, R. H., 1941. “The Soft Anatomy of Bothriolepis”, J. Paleont., 15, 553561.
Denison, R. H., 1956. “A Review of the Habitat of the Earliest Vertebrates”, Fieldiana: Geol., 11, 357457.
Dineley, D. L. and Williams, B. P. J., 1968. “Sedimentation and paleoecology of the Devonian Escuminac Formation and related strata, Escuminac Bay, Quebec”, Spec. Pap. Geol. Soc. Am., 129.
Eaton, T. H., 1951. “Origin of Tetrapod Limbs”, Am. Midl. Nat., 46, 245251.
Eaton, T. H., 1960. “The Aquatic Origin of Tetrapods”, Trans. Kans. Acad. Sci., 63, 115120.
Eaton, T. H. and Stewart, P. L., 1960. “A New Order of Fish-like Amphibia from the Pennsylvanian of Kansas”, Univ. Kans. Publs Mus. Nat. Hist., 12, 217240.
Evans, F. G. and Krahl, V. E., 1945. “The Torsion of the Humerus: a phylogenetic survey from fish to man”, Am. J. Anat., 76, 303337.
Ewer, D. W., 1955. “Tetrapod Limb”, Science, N.Y., 122, 467468.
Fell, H., 1939. “The Origin and Developmental Mechanics of the Avian Sternum”, Phil. Trans. Roy. Soc, B, 229, 407–63.
Gegenbaur, C., 1865. Untersuchungen zur vergleichenden Anatomie der Wirbelthiere. II. Schultergürtel der Wirbelthiere. Brustflosse der Fische. Leipzig: Engelmann.
Gero, D. R., 1952. “The Hydrodynamic Aspects of Fish Propulsion”, Am. Mus. Novit., 1601, 132.
Goin, C. J. and Goin, O. B., 1956. “Further Comments on the Origin of the Tetrapods”, Evolution, N.Y., 10, 440441.
Goodrich, E. S., 1901. “On the Pelvic Girdle and Fin of Eusthenopteron”, Q. Jl Microsc. Sci., 45, 311324, pl. 16.
Gregory, W. K., 1911. “The Limbs of Eryops and the Origin of Paired Limbs from Fins”, Science, N.Y., 33, 508509.
Gregory, W. K., 1913. “Crossopterygian Ancestry of the Amphibia”, Science, N.Y., 37, 806808.
Gregory, W. K., 1915. “Present Status of the Problem of the Origin of the Tetrapoda, with special reference to the skull and paired limbs”, Ann. N.Y. Acad. Sci., 26, 317383.
Gregory, W. K., 1935. “Further Observations on the Pectoral Girdle and Fin of Sauripterus taylori Hall, a crossopterygian fish from the Upper Devonian of Pennsylvania, with special reference to the origin of the pentadactylate extremities of Tetrapoda”, Proc. Am. Phil. Soc., 75, 673690.
Gregory, W. K., 1949. “The Humerus from Fish to Man”, Am. Mus. Novit., 1400, 154.
Gregory, W. K., 1951. Evolution Emerging. New York: Macmillan.
Gregory, W. K., Miner, R. W. and Noble, G. K., 1923. “The Carpus of Eryops, and the Structure of the Primitive Chiropterygium”, Bull. Am. Mus. Nat. Hist., 48, 279288.
Gregory, W. K. and Raven, H. C., 1941. “Studies on the Origin and Early Evolution of Paired Fins and Limbs”, Ann. N.Y. Acad. Sci., 42, 273360.
Gregory, W. K., Rockwell, H. and Evans, F. G., 1939. “Structure of the Vertebral Column in Eusthenopteron foordi Whiteaves”, J. Paleont., 13, 126129.
Gross, W., 1954. “Zur Phylogenie der Schultergürtels”, Paläont. Z., 28, 2040.
Grove, A. S. and Newell, G. E., 1936. “A Mechanical Investigation into the Effectual Action of the Caudal Fin of Some Aquatic Chordates”, Ann. Mag. Nat. Hist., 17, 280290.
Gunter, G., 1956. “Origin of the Tetrapod Limb”, Science, N. Y., 123, 495496.
Hanson, F. B., 1919. “The Ontogeny and Phylogeny of the Sternum”, Am. J. Anat., 26, 41115, pl. I–XII.
Harris, J. E., 1936. “The Role of the Fins in the Equilibrium of the Swimming Fish. I. Wind-tunnel Tests on a Model of Mustelus canis Mitchell”, J. Exp. Biol., 13, 476493.
Harris, J. E., 1937. “The Mechanical Significance of the Position and Movements of the Paired Fins of the Teleostei”, Pap. Tortugas Lab., 31, 171189.
Harris, J. E., 1938. “The Role of the Fins in the Equilibrium of the Swimming Fish. II. The Role of the Pelvic Fins”, J. Exp. Biol., 15, 3247.
Harris, V. A., 1960. “On the Locomotion of the mud-skipper Periophthalmus koelreuteri (Pallas): (Gobiidae)”, Proc. Zool. Soc. Lond., 134, 107135.
Holmgren, N., 1933. “On the Origin of the Tetrapod Limb”, Acta Zool., Stockh. 14, 185295.
Holmgren, N., 1939. “Contribution to the Question of the Origin of the Tetrapod Limb”, Acta Zool, Stockh., 20, 89124.
Holmgren, N., 1949. “On the Tetrapod Limb Problem—Again”, Acta Zool., Stockh., 30, 485508.
Howell, A. B., 1933. “Morphogenesis of the Shoulder Architecture. Part II. Pisces”, Q. Rev. Biol, 8, 434456.
Howell, A. B., 1935. “Morphogenesis of the Shoulder Architecture. Part III. Amphibia”, Q. Rev. Biol., 10, 397431.
Howell, A. B., 1938. “Morphogenesis of the Architecture of Hip and Thigh”, J. Morph., 62, 177218.
Hussakof, L., 1912. “Notes on Devonic Fishes from Scaumenac Bay, Quebec”, Bull. N.Y. St. Mus., 158, 127139, pl. I–III.
Inger, R. F., 1957. “Ecological Aspects of the Origins of the Tetrapods”, Evolution, N.Y., 11, 373376.
Jarvik, E., 1942. “On the Structure of the Snout of Crossopterygians and Lower Gnathostomes in General”, Zool. Bidr. Upps., 21, 235675.
Jarvik, E., 1944 a. “The Dermal Bones, Sensory Canals and Pit-lines of the Skull in Eusthenopteron foordi Whiteaves, with some remarks on E. säve-söderberghi Jarvik”, K. Svenska Vetensk-Akad. Handl., 21 (3), 148.
Jarvik, E., 1944 b. “On the Exoskeletal Shoulder-girdle of Teleostomian Fishes, with special reference to Eusthenopteron foordi Whiteaves”, K. Svenska Vetensk-Akad. Handl., 21 (7), 132.
Jarvik, E., 1948. “On the Morphology and Taxonomy of the Middle Devonian Osteolepid Fishes of Scotland”, K. Svenska Vetensk-Akad. Handl., 25 (1), 1301, pl. 1–37.
Jarvik, E., 1952. “On the Fish-like Tail in the Ichthyostegid Stegocephalians”, Meddr Grønland, 114 (12), 190, pl. 1–21.
Jarvik, E., 1954. “On the Visceral Skeleton in Eusthenopteron with a Discussion of the Parasphenoid and Palatoquadrate in Fishes”, K. Svenska Vetensk-Akad. Handl., 5 (1), pp. 1104.
Jarvik, E., 1955 a. “The Oldest Tetrapods and Their Forerunners”, Scient. Mon., N.Y., 80, 141154.
Jarvik, E., 1955 b. “Ichthyostegalia”. In Piveteau, J., Ed., Traité de Paléontologie, 5, 5366. Paris: Masson.
Jarvik, E., 1959. “Dermal Fin-rays and Holmgren's Principle of Delamination”, K. Svenska Vetensk-Akad. Handl., 6 (1), 151, pl. 1–4.
Jarvik, E., 1960. Théories de l'Évolution des Vertébrés, reconsidérées à la lumière des Récentes Découvertes sur les Vertébrés Inférieures. Paris: Masson.
Jarvik, E., 1963. “The Composition of the Intermandibular Division of the Head in Fish and Tetrapods and the Diphyletic Origin of the Tetrapod Tongue”, K. Svenska Vetensk-Akad. Handl., 9 (1), 174.
Jarvik, E., 1964. “Specialisations in Early Vertebrates”, Annls Soc. Roy. Zool. Belg., 94, 1195.
Jarvik, E., 1965 a. “Die Raspelzunge der Cyclostomen und die pentadactyle Extremität der Tetrapoden als Beweise für monophyletische Herkunft”, Zool. Anz., 175, 101143.
Jarvik, E., 1965 b. “On the Origin of Girdles and Paired Fins”, Israel J. Zool., 14, 141172.
Jarvik, E., 1966. “Remarks on the Structure of the Snout in Megalichthys and Certain Other Rhipidistid Crossopterygians”, Ark. Zool., 19, 4198, pl. 1–5.
Johnels, A. G. and Svensson, G. S. O., 1954. “On the Biology of Protopterus annectens Owen”, Ark. Zool., 7, 131158.
Klaatsch, H., 1896. “Die Brustflosse der Crossopterygier”. In Haeckel, E. H. P. A. et al. Festschrift zum siebenzigsten Geburtstage von C. Gegenbaur, 1, 261391. Leipzig: Engelmann.
LeDamany, P., 1903. “Les Torsions Osseuses. Leur role dans la transformation des membres”, J. Anat. Physiol, Paris, 39, 126–134, 161–165, 313337.
Lehman, J.-P., 1947. “Description de quelques Exemplaires de Cheirolepis canadensis (Whiteaves)”, K. Svenska Vetensk-Akad. Handl., 24 (4), 140, pl. 1–9.
Manzii, S. F., 1962. “Adaptatziya Chrebetnych do Nazemnogo Peresuvannya”, Pitannia, Evol. Morf., Akad Nauk, URSS, 18, 1219. (English Translation by N.L.L., No. RTS 3909, “Adaptation of the Vertebrates to Terrestrial Locomotion”.)
Marinelli, W., 1946. “Der Schultergürtel der Wirbeltiere. Funktions analytische Studie”, Öst. Zool. Z., 1, 129164.
Marshall, N. B., 1965. The Life of Fishes. London.
Martin, C. P., 1933. “Cause of Torsion of the Humerus and of the notch on the anterior edge of the glenoid cavity of the scapula”, J. Anat., 67, 573582.
Miles, R. S., 1965. “Some Features in the Cranial Morphology of Acanthodians and the Relationships of the Acanthodii”, Acta Zool., Stockh., 46, 233255.
Millot, J. and Anthony, J., 1958 a. Anatomie de Latimeria chalumnae. Tome I. Squelette, Muscles et Formations de Soutien. Paris: C.N.R.S.
Millot, J., 1958 b. “Crossopterygiens Actuels. Latimeria chalumnae, Dernier des Crossopterygiens”. In Grassé, J.-P., Ed., Traité de Zoologie, 13 (3), 25532597. Paris: Masson.
Miner, R. W., 1925. “The Pectoral Limb of Eryops and Other Primitive Tetrapods”, Bull. Am. Mus. Nat. Hist., 51, 145312.
Nielsen, E., 1942. “Studies on Triassic Fishes from East Greenland. I. Glaucolepis and Boreosomus”, Meddr Grønland, 138, 1403, pl. 1–30.
Olson, E. C., 1961. “Jaw Mechanisms: Rhipidistians, Amphibians, Reptiles”, Am. Zool., 1, 205215.
Orton, G. L., 1954. “Original Adaptive Significance of the Tetrapod Limb”, Science, N.Y., 120, 10421043.
Parrington, F. R., 1967. “The Vertebrae of Early Tetrapods”, Colloques Int. Cent. Natn. Rech. Scient., 163, 269279.
Patten, W., 1912. The Evolution of Vertebrates and Their Kin. London.
Petronievics, B., 1918. “The Pectoral Fin of Eusthenopteron”, Ann. Mag. Nat. Hist., 2, 471476.
Rayner, D. H., 1958. “The Geological Environment of Fossil Fishes”. In Westoll, T. S., Ed., Studies on Fossil Vertebrates, 129156. London: Athlone Press.
Rayner, D. H., 1963. “The Achanarras Limestone of the Middle Old Red Sandstone, Caithness, Scotland”, Proc. Yorks. Geol. Soc., 34, 117138, pl. 17–18.
Romer, A. S., 1922. “The Locomotor Apparatus of Certain Primitive and Mammal-like Reptiles”, Bull. Am. Mus. Nat. Hist., 46, 517606, pl. XXVII–XLVI.
Romer, A. S., 1924. “Pectoral Limb Musculature and Shoulder-Girdle Structure in Fish and Tetrapods”, Anat. Rec., 27, 119143.
Romer, A. S., 1933. “Eurypterid Influence on Vertebrate History”, Science, N.Y., 78, 114117.
Romer, A. S., 1941. Man and the Vertebrates. (3rd Ed.). University of Chicago Press.
Romer, A. S., 1942. “The Development of the Tetrapod Limb Musculature—The Thigh of Lacerta”, J. Morph., 71, 251298.
Romer, A. S., 1944. “The Development of the Tetrapod Limb Musculature—The Shoulder Region of Lacerta”, J. Morph., 74, 141.
Romer, A. S., 1945. Vertebrate Paleontology. (2nd Edn.). University of Chicago Press.
Romer, A. S., 1956 a. Osteology of the Reptiles. University of Chicago Press.
Romer, A. S., 1956 b. “The Early Evolution of Land Vertebrates”, Proc. Am. Phil. Soc., 100, 157167.
Romer, A. S., 1958. “Tetrapod Limbs and Early Tetrapod Life”, Evolution, N.Y., 12, 365369.
Romer, A. S., 1962. The Vertebrate Body. (3rd Edn). London: Saunders.
Romer, A. S. and Byrne, F., 1931. “The pes of Diadectes: Notes on the Primitive Limb”, Palaeobiologica, 4, 2448.
Romer, A. S. and Grove, B. H., 1935. “Environment of the Early Vertebrates”, Am. Midi. Nat., 16, 805856.
Romer, A. S. and Olson, E. C., 1954. “Aestivation in a Permian Lungfish”, Breviora, 30, pp. 18.
Romer, A. S. and Price, L. I., 1940. “Review of the Pelycosauria”, Spec. Pap. Geol. Soc. Am., 28, 1538, pl. 1–46.
Russell, L. S., 1939. “Notes on the Occurrence of Fossil Fishes in the Upper Devonian of Maguasha, Quebec”, Contrib. Roy. Ont. Mus. Palaeont., 2, pp. 110, pl. 1.
Säve-Söderbergh, G., 1932. “Preliminary Note on Devonian Stegocephalians from East Greenland”, Meddr Grønland, 94, 1107, pl. I–XXII.
Schaeffer, B., 1941. “A Revision of Coelacanthus newarki and notes on the Evolution of the Girdles and Basal Plates of the Median Fins in the Coelacanthini”, Am. Mus. Novit., 1110, 117.
Schaeffer, B., 1965. “The Rhipidistian—Amphibian Transition”, Am. Zool., 5, 267275.
Schaeffer, B., 1967. “Osteichthyan Vertebrae”, J. Linn. Soc. (Zool.), 47, 185195.
Schaeffer, B. and Rosen, D. E., 1961. “Major Adaptive Levels in the Evolution of the Actinopterygian Feeding Mechanism”, Am. Zool., 1, 187204.
Seno, T., 1961. “The Origin and Evolution of the Sternum”, Anat. Anz., 110, 97101.
Stensiö, E. A., 1922. “Notes on Certain Crossopterygians”, Proc. Zool. Soc. Lond., 1922, 12411271, pl. 1.
Stensiö, E. A., 1925. “Note on the Caudal Fin of Eusthenopteron”, Ark. Zool., 17B, (11) 13.
Stensiö, E. A., 1932. “Triassic Fishes from East Greenland”, Meddr Grønland, 83, 1345, Atlas.
Stensiö, E. A., 1963. “The Brain and the Cranial Nerves in Fossil, Lower Craniate Vertebrates”, Skr. Norske Vidensk-Akad. (Mat.-Nat. K1.), 13, pp. 1120.
Sternberg, R. M., 1941. “Cranial Morphology of the Devonian Crossopterygian Eusthenopteron”, Univ. Toronto Stud. Geol. Ser., 45, 148, pl. I–V.
Tchernavin, V. V., 1953. The Feeding Mechanisms of a Deep Sea Fish. Chauliodus sloani Schneider. London: Br. Mus. Nat. Hist.
Thomson, K. S., 1962. “Rhipidistian Classification in Relation to the Origin of Tetrapods”, Breviora, 117, 112.
Thomson, K. S., 1964 a. “The Ancestry of the Tetrapods”, Sci. Prog., Lond., 52, 451–59.
Thomson, K. S., 1964 b. “The Comparative Anatomy of the Snout in Rhipidistian Fishes”, Bull. Mus. Comp. Zool. Harv., 131, 315357.
Thomson, K. S., 1967. “Mechanisms of Intracranial Kinetics in Fossil rhipidistian fishes (Crossopterygii) and their relatives”, J. Linn. Soc. (Zool.) 46, 223253.
Thomson, K. S. and Vaughn, P. P., 1968. “Vertebral Structure in Rhipidistia (Osteichthyes, Crossopterygii) with Description of a new Permian Genus”, Postilla, 127, 119.
Toombs, H. A., 1948. “The Use of Acetic Acid in the Development of Vertebrate Fossils”, Museums J., 48, 5455.
Toombs, H. A. and Rixon, A. E., 1959. “The Use of Acids in the Preparation of Vertebrate Fossils”, Curator, 11, 304312.
Traquair, R. H., 1889. “On a New Species of Dipterus”, Geol. Mag., 6, 9799.
Vaughn, P. P., 1964. “Evidence of Aestivating Lungfish from the Sangre de Cristo Formation, Lower Permian of Northern New Mexico”, Contr. Sci., 80, 17.
Vorobjeva, E. I., 1962. “Rizodontnye Kisteperye Ryby Glavnogo Devonskogo Polya S.S.S.R.”, Trudy Paleont. Inst., 94, 1108, pl. I–XXVIII. (English Translation by N.L.L., No. RTS 3911, “Rhizodont Crossopterygian Fishes from the Main Devonian Area of the U.S.S.R.”).
Von Wahlert, G., 1961. “Über einige Skelett-Formen von Fisch-Flossen und ihre phylogenetische Bedeutung”, Zool. Anz., Suppl., 25, 498508.
Warburton, F. E. and Denman, N. S., 1961. “Larval Competition and the Origin of Tetrapods”, Evolution, N.Y., 15, 566.
Watson, D. M. S., 1913. “On the Primitive Tetrapod Limb”, Anat. Anz., 44, 2427.
Watson, D. M. S., 1917. “The Evolution of the Tetrapod Shoulder Girdle and Forelimb”, J. Anat., 52, 163.
Watson, D. M. S., 1921. “On the Coelacanth Fish”, Ann. Mag. Nat. Hist., 8, 320337.
Watson, D. M. S., 1926. “The Evolution and Origin of the Amphibia”, Phil. Trans. Roy. Soc, B, 214, 189257.
Westoll, T. S., 1937. “The Old Red Sandstone Fishes of the North of Scotland, particularly of Orkney and Shetland”, Proc. Geol. Ass., 48, 1345.
Westoll, T. S., 1938. “The Ancestry of the Tetrapods”, Nature, Lond., 141, 127.
Westoll, T. S., 1943 a. “The Origin of the Tetrapods”, Biol. Rev., 18, 7898.
Westoll, T. S., 1943 b. “The Origin of the Primitive Tetrapod Limb”, Proc. Roy. Soc, B, 131, 373393.
Westoll, T. S., 1949. “On the Evolution of the Dipnoi”. In Jepsen, G. L., Simpson, G. G. and Mayr, E., Eds., Genetics Palaeontology and Evolution, 121184, Princeton.
Westoll, T. S., 1958. “The Origin of Continental Vertebrate Faunas”, Trans. Geol. Soc Glasg., 23, 127.
Whiteaves, J. F., 1881. “On Some Remarkable Fossil Fishes from the Devonian Rocks of Scaumenac Bay, P.Q. with descriptions of a new Genus and three New Species”, Can. Nat., 10, 2735.
Whiteaves, J. F., 1888. “Illustrations of the Fossil Fishes of the Devonian Rocks of Canada. Part II”, Trans. Proc. Roy. Soc. Canada, 6, 7796, pl. V–X.
Williams, B. P. J. and Dineley, D. L., 1966. “Studies on the Devonian Strata of Chaleur Bay, Quebec”, Marit. Sediments, 2, 710.
Williams, E. E., 1959. “Gadow's Arcualia and the Development of Tetrapod Vertebrae”, Q. Rev. Biol., 34, 132.
Williston, S. W., 1909. “New or Little-known Permian Vertebrates. Trematops, New Genus”, J. Geol., 17, 636658.
Woodward, A. S., 1893. “Note on a Case of Subdivision of the Median Fin of a Dipnoan Fish”, Ann. Mag. Nat. Hist., 11, 241242.
Woodward, A. S., 1898. Outlines of Vertebrate Palaeontology for Students of Zoology. Cambridge University Press.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Earth and Environmental Science Transactions of The Royal Society of Edinburgh
  • ISSN: 1755-6910
  • EISSN: 1755-6929
  • URL: /core/journals/earth-and-environmental-science-transactions-of-royal-society-of-edinburgh
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed