Abstract
A medial inflection of the mandibular angular process is present in most marsupials. The few living marsupials that lack this trait either are very specialized forms (e.g., Tarsipes) or show a medial inflection at some point in development that is lost in later ontogenetic stages (cf. Dactylopsila and Phascolarctos). A medially inflected angular process is not present in any known extant or extinct placental (including all Cretaceous taxa that preserve the back of the dentary bone). Some extant placentals with enlarged auditory bullae evolved a medial flange of the angular process as a strategy to increase gape, but this is not homologous to the marsupial condition. We conclude that the medially inflected angular process is a shared derived trait of extant and extinct marsupials. The significant diversity in the form of the medially inflected mandibular angular process in marsupials, documented here for 53 taxa, shows a general relation to dietary adaptations. Herbivores (with well-developed masseter and medial pterygoid muscles) tend to have a shelf-like angular process, while small, insectivorous marsupials generally have a rod-like angular process. A close connection between the angular process and the ectotympanic is maintained during early postnatal development in all marsupials examined, a relation not seen in the placentals examined. A previous hypothesis suggested that the angular process plays a role in hearing in pouch-young Monodelphis. Data on the maturation of the auditory system does not support this hypothesis. Currently there are no data on differences in muscular anatomy or mastication between marsupials and placentals that could serve as a causal explanation for the difference in adult form of the angular process between the two groups.
Similar content being viewed by others
LITERATURE CITED
Abbie, A. A. (1939). A masticatory adaptation peculiar to some diprotodont marsupials. Proc. Zool. Soc. London B109: 261–279.
Aitkin, L., Nelson, J., Martsi-McClintock, A., and Swann, S. (1996). Features of the structural development of the inferior colliculus in relation to the onset of hearing in a marsupial: The northern quoll, Dasyurus hallucatus. J. Comp. Neurol. 375: 77–88.
Archer, M. (1984). Origins and early radiations of marsupials. In: Vertebrate Zoogeography and Evolution in Australasia, M. Archer and G. Clayton, eds., pp. 585–624, Hesperian Press, Perth.
Archer, M., Hand, S., and Godthelp, H. (1988). A new order of Tertiary zalambdodont marsupials. Science 239: 1528–1531.
Archer, M., Hand, S. J., and Godthelp, H. (1991). Riversleigh. The Story of Animals in Ancient Rainforests of Inland Australia, Reed Books, New South Wales.
Atchley, W. R. (1993). Genetic and developmental aspects of variability in the mammalian mandible. In: The Skull, Vol. 1, J. Hanken and B. K. Hall, eds., pp. 207–247, University of Chicago Press, Chicago.
Atchley, W. R., and Hall, B. K. (1991). A model for development and evolution of complex morphological structures. Biol. Rev. 66: 101–157.
Avis, V. (1961). The significance of the angle of the mandible: An experimental and comparative study. Am. J. Phys. Anthropol. 19: 55–61.
Barbour, R. A. (1963). The musculature and limb plexuses of Trichosurus vulpecula. Aust. J. Zool. 11: 488–610.
Baverstock, P. R., Richardson, B. J., Birrell, J., and Krieg, M. (1989). Albumin immunologic relationships of the Macropodidae (Marsupialia). Syst. Zool. 38: 38–50.
Cant, N. B. (1997). Structural development of the mammalian auditory pathways. In: Development of the Auditory System, E. Rubel, R. Fay, and A. Popper, eds., Springer-Verlag, New York (in press).
Carroll, R. L. (1988). Vertebrate Paleontology and Evolution, W. H. Freeman, New York.
Cifelli, R. L. (1993a). Early Cretaceous mammal from North America and the evolution of marsupial dental characters. Proc. Natl. Acad. Sci. USA 90: 9413–9416.
Cifelli, R. L. (1993b). Theria of metatherian-eutherian grade and the origin of marsupials. In: Mammal Phylogeny. Mesozoic Differentiation. Multituberculates, Monotremes, Early Therians and Marsupials, F. S. Szalay, M. J. Novacek, and M. C. McKenna, eds., pp. 205–215, Springer-Verlag, New York.
Clark, C. T., and Smith, K. K. (1993). Cranial osteogenesis in Monodelphis domestica (Didelphidae) and Macropus eugenii (Macropodidae). J. Morphol. 215: 119–149.
Clemens, W. A., and Kielan-Jaworowska, Z. (1979). Multituberculata. In: Mesozoic Mammals. The First Two Thirds of Mammalian History, J. A. Lillegraven, Z. Kielan-Jaworowska, and W. A. Clemens, eds., pp. 99–149, University of California Press, Berkeley.
Crompton, A. W. (1971). The origin of the tribosphenic molar: In: Early Mammals, Kermack, D. M., and Kermack, K. A., eds., Zool. J. Linn. Soc. 50 (Suppl. 1): 65–87.
Crompton, A. W., and Hiiemae, K. (1970). Molar occlusion and mandibular movements during occlusion in the American opossum, Didelphis marsupialis L. Zool. J. Linn. Soc. 49: 21–47.
Crompton, A. W., and Hylander, W. L. (1986). Changes in mandibular function following the acquisition of a dentary-squamosal jaw articulation. In: The Ecology and Biology of Mammal-like Reptiles, N. Hotton III, P. D. MacLean, J. J. Roth, and E. C. Roth, eds., pp. 263–281, Smithsonian Institution Press, Washington, DC.
Crompton, A. W., and Parker, P. (1978). Evolution of the mammalian masticatory apparatus. Am. Sci. 66: 192–201.
Crompton, A. W., Thexton, A. J., Parker, P., and Hiiemae, K. (1977). The activity of the jaw and hyoid musculature in the Virginia opossum, Didelphis virginiana. In: The Biology of Marsupials, B. Stonehouse and D. Gilmore, eds., pp. 287–305, Macmillan, London.
Darwin, C. (1859). The Origin of Species, John Murray, London.
Dashzeveg, D., and Kielan-Jaworowska, Z. (1984). The lower jaw of an aegialodontid mammal from the Early Cretaceous of Mongolia. Zool. J. Linn. Soc. 82: 217–227.
Davison, C. V., and Young, W. G. (1990). The muscles of mastication of Phascolarctos cinereus (Phascolarctidae: Marsupialia). Aust. J. Zool. 38: 227–240.
Ellis, W. A. H., Melzer, A., Green, B., Newgrain, K., Hindell, M. A., and Carrick, F. N. (1995). Seasonal variation in water flux, field metabolic rate and food consumption of free-ranging koalas (Phascolarctos cinereus). Aust. J. Zool. 43: 59–68.
Emmons, L. H., and Feer, F. (1990). Neotropical Rainforest Mammals, A Field Guide, University of Chicago, Chicago.
Filan, S. L. (1990). Myology of the head and neck of the bandicoot (Marsupialia: Peramelemorphia). Aust. J. Zool. 38: 617–634.
Flannery, T. (1987). The relationships of the macropodoids (Marsupialia) and the polarity of some morphological features within the Phalangeriformes. In: Possums and Opossums: Studies in Evolution, M. Archer, ed., pp. 741–747, Surrey Beatty & Sons and the Royal Zoological Society of New South Wales, Sydney.
Flannery, T. F. (1989). Phylogeny of the Macropodidae; A study in convergence. In: Kangaroos, Wallabies and Rat-Kangaroos, G. Grigg, P. Jarman, and I. Hume, eds., pp. 1–46, Beatty & Sons Pty Ltd., New South Wales.
Flannery, T. F. (1990). Mammals of New Guinea, Robert Brown & Associates, Carina, Queensland.
Flannery, T. (1995). Mammals of the South-West Pacific & Moluccan Islands, Comstock/Cornell, Ithaca, NY.
Flower, W. H. (1885). An Introduction to the Osteology of the Mammalia, MacMillan, London.
Gambaryan, P. P., and Kielan-Jaworowska, Z. (1995). Masticatory musculature of Asian taeniolabidoid multituberculate mammals. Acta Palaeontol. Pol. 40: 45–108.
Goin, F. J. (1997). New clues for understanding Neogene marsupial radiations. In: Vertebrate Paleontology in the Neotropics, R. F. Kay, R. Cifelli, R. H. Madden, and J. Flynn, eds., pp. 185–204, Smithsonian Institution Press, Washington, DC.
Herring, S. W. (1985). The ontogeny of mammalian mastication. Am. Zool. 25: 339–349.
Hiiemäe, K., and Jenkins, F. A., Jr. (1969). The anatomy and internal architecture of the muscles of mastication in Didelphis marsupialis. Postilla 140: 1–49.
Howell, A. B. (1932). The saltatorial rodent Dipodomys: The functional and comparative anatomy of its muscular and osseous systems. Proc. Am. Acad. Arts Sci. 67: 377–536.
Kay, R. F. (1984). On the use of anatomical features to infer foraging behavior in extinct primates. In: Adaptations for Foraging in Nonhuman Primates, P. S. Rodman and J. G. H. Cant, eds., pp. 21–53, Columbia University Press, New York.
Kay, R. F., and Cartmill, M. (1977). Cranial morphology and adaptations of Palaechthon nacimienti and other Paromomyidae (Plesiadapoidea, ?Primates), with a description of a new genus and species. J. Hum. Evol. 6: 19–53.
Kay, R. F., and Hiiemae, K. M. (1974). Jaw movement and tooth use in recent and fossil primates. Am. J. Phys. Anthropol. 40: 227–56.
Kielan-Jaworowska, Z. (1975). Preliminary description of two new eutherian genera from the Late Cretaceous of Mongolia. Paleontol. Pol. 33: 5–15.
Kielan-Jaworowska, Z., and Nessov, L. A. (1990). On the metatherian nature of the Deltatheroida, a sister group of the Marsupialia. Lethaia 23: 1–10.
Kirsch, J. A. W., and Palma, R. E. (1995). DNA/DNA hybridization studies of carnivorous marsupials. V. A further estimate of relationships among opossums (Marsupialia: Didelphidae). Mammalia 59: 403–425.
Kirsch, J. A. W., Krajewski, C., Springer, M. S., and Archer, M. (1990a). DNA-DNA hybridisation studies of carnivorous marsupials II. Relationships among dasyurids (Marsupialia: Dasyuridae). Aust. J. Zool. 38: 673–696.
Kirsch, J. A. W., Springer, M. S., Krajewski, C., Archer, M., Aplin, K., and Dickerman, A. W. (1990b). DNA-DNA hybridisation studies of carnivorous marsupials I. The intergeneric relationships of bandicoots (Marsupialia: Perameloidea). J. Mol. Evol. 30: 434–448.
Kirsch, J. A. W., Lapointe, F.-J., and Springer, M. S. (1997). DNA-hybridisation studies of marsupials and their implications for metatherian classification. Aust. J. Zool. (in press).
Krajewski, C., Painter, J., Buckley, L., and Westerman, M. (1994). Phylogenetic structure of the marsupial family Dasyuridae based on cytochrome b DNA sequences. J. Mammal. Evol. 2: 25–34.
Krause, D. W. (1982). Jaw movement, dental function, and diet in the Paleocene multituberculate Ptilodus. Paleobiology 8: 265–281.
Kuhn, H.-J. (1971). Die Entwicklung und Morphologie des Schädels von Tachyglossus aculeatus. Abh. Senckenberg. Naturforsch. Ges. 528: 1–224.
Lee, A. K., and Cockburn, A. (1985). Evolutionary Ecology of Marsupials, Cambridge University Press, Cambridge.
Lillegraven, J. A. (1969). Latest Cretaceous mammals of upper part of Edmonton Formation of Alberta, Canada, and review of marsupial-placental dichotomy in mammalian evolution. Univ. Kansas Paleontol. Contrib. 50: 1–122.
Lillegraven, J. A., Kielan-Jaworowska, Z., and Clemens, W. A. (1979). Mesozoic Mammals: The First Two-Thirds of Mammalian History, University of California Press, Berkeley.
Luckett, W. P. (1994). Suprafamilial relationships within Marsupialia: Resolution and discordance from multidisciplinary data. J. Mammal. Evol. 2: 255–283.
MacDonald, D. (ed.). (1984). The Encyclopaedia of Mammals, Facts on File, New York.
MacPhee, R. D. E. (1981). Auditory regions of primates and eutherian insectivores: Morphology, ontogeny and character analysis. Contrib. Primatol. 18: 1–282.
Maier, W. (1978). Die Evolution der tribosphenischen Säugetiermolaren. Sonderb. Naturw. Ver. Hamburg 3: 41–60.
Maier, W. (1987). Der Processus angularis bei Monodelphis domestica (Didelphidae: Marsupialia) und seine Beziehungen zum Mittelohr: Eine ontogenetische und evolutionsmorphologische Untersuchung. Gegenbaurs morphol. Jahrb. 133: 123–161.
Maier, W. (1989). Morphologische Untersuchungen am Mittelohr der Marsupialia. Z. zool. Syst. Evolut.-forsch. 27: 149–168.
Maier, W. (1990). Phylogeny and ontogeny of mammalian middle ear structures. Netherl. J. Zool. 40: 55–74.
Maier, W. (1993). Cranial morphology of the therian common ancestor, as suggested by the adaptations of neonate marsupials. In: Mammal Phylogeny. Mesozoic Differentiation, Multituberculates, Monotremes, Early Therians and Marsupials, F. S. Szalay, M. J. Novacek, and M. C. McKenna, eds., pp. 165–181, Springer-Verlag, New York.
Marshall, L. G. (1978). Dromiciops australis. Mammal. Species 99: 1–5.
Marshall, L. G. (1979). Evolution of metatherian and eutherian (mammalian) characters: A review based on cladistic methodology. Zool. J. Linn. Soc. 66: 369–410.
Marshall, L. G., and Kielan-Jaworowska, Z. (1992). Relationships of the dog-like marsupials, deltatheroidans and early tribosphenic mammals. Lethaia 25: 361–374.
Marshall, L. G., and Muizon, C. de (1995). Part II: The Skull. In: Pucadelphys andinus (Marsupialia, Mammalia) from the Early Paleocene of Bolivia, C. de Muizon, ed., Mém. Mus. natn. Hist. nat. Paris 165: 21–90.
Mellett, J. S. (1980). Function of the inflected mandibular angle in marsupials. Abstracts of papers and posters. Sixtieth annual meeting American Society of Mammalogists.
Mellett, J. S., and Szalay, F. S. (1968). Kennatherium shirensis (Mammalia, Palaeoryctoidea), a new didymoconid from the Eocene of Asia. Am. Mus. Novitates 2342: 1–7.
Miao, D. (1988). Skull morphology of Lambdopsalis bulla (Mammalia, Multituberculata) and its implications to mammalian evolution. Contrib. Geol. Univ. Wyo. Spec. Paper 4: 1–104.
Murray, P., Wells, R., and Plane, M. (1987). The cranium of the Miocene thylacoleonid, Wakaleo vanderleuri: Click go to shears—a fresh bite at thylacoleonid systematics. In: Possums and Opossums—Studies in Evolution, M. Archer, ed., pp. 433–466, Surrey Beatty & Sons and the Royal Zoological Society of New South Wales, Sydney.
Nikolai, J. C., and Bramble, D. M. (1983). Morphological structure and function in desert heteromyid rodents. Great Basin Nat. Mem. 7: 44–64.
Norbury, G. L., Sanson, G. D., and Lee, A. K. (1989). Feeding ecology of the Macropodoidea. In: Kangaroos, Wallabies, and Rat-kangaroos, G. Grigg, P. Jarman, and I. Hume, eds., pp. 169–178, Surrey Beatty & Sons Pty. Ltd., New South Wales.
Novacek, M. J. (1986). The skull of leptictid insectivorans and the higher-level classification of eutherian mammals. Bull. Am. Mus. Nat. Hist. 183: 1–112.
Novacek, M. J. (1995). New therian mammals from the Cretaceous of Mongolia. J. Vert. Paleontol. 15: 46A.
Novacek, M. J., Norell, M. A., Dingus, L., and Dashzeveg, D. (1996). Dinosaurs, mammals, birds, and lizards from the Late Cretaceous Ukhaa Tolgod Fauna, Mongolia. J. Vert. Paleontol. 16: 56A.
Nowak, R. M. (1991). Walker's Mammals of the World, The John Hopkins University Press, Baltimore.
O'Connell, M. (1983). Marmosa robinsoni. Mammal. Species 203: 1–6.
Oron, U., and Crompton, A. W. (1985). A cineradiographic and electromyographic study of mastication in Tenrec ecaudatus. J. Morphol. 185: 155–182.
Osborn, D. J., and Helmy, I. (1980). The contemporary land mammals of Egypt (including Sinai). Fieldiana Zool. 1–579.
Osgood, W. H. (1921). A monographic study of the American marsupial, Caenolestes. Publ. Field Mus. Nat. Hist. Zool. Ser. 14: 1–156.
Parker, P. J. (1977). Aspects of the Biology of Bettongia penicillata, Ph.D. dissertation, Yale University, New Haven, CT.
Pascual, R., Goin, F. J., and Carlini, A. A. (1994). New data on the Groeberiidae: Unique late Eocene-early Oligocene South American marsupials. J. Vert. Paleontol. 14: 247–259.
Paula Couto, C. d. (1952). Fossil mammals from the beginning of the Cenozoic of Brazil. Marsupialia: Polydolopidae and Borhyaenidae. Am. Mus. Novitates 1559: 1–27.
Pérez-Hernández, R., Soriano, P., and Lew, D. (1994). Marsupiales de Venezuela, Cuadernos Lagoven, Caracas.
Presley, R. (1993). Development and the phylogenetic features of the middle ear region. In: Mammal Phylogeny. Mesozoic Differentiation. Multituberculates, Monotremes, Early Therians and Marsupials, F. S. Szalay, M. J. Novacek, and M. C. McKenna, eds., pp. 21–29, Springer-Verlag, New York.
Radinsky, L. (1985). Patterns in the evolution of ungulate jaw shape. Am. Zool. 25: 303–314.
Reig, O. A., and Simpson, G. G. (1972). Sparassocynus (Marsupialia, Didelphidae), a peculiar mammal from the late Cenozoic of Argentina. J. Zool. Lond. 167: 511–539.
Reimer, K. (1996). Ontogeny of hearing in the marsupial, Monodelphis domestica, as revealed by brainstem auditory evoked potentials. Hear. Res. 92: 143–150.
Ride, W. D. L. (1959). Mastication and taxonomy in the macropodine skull. Syst. Ass. Publ. 3: 33–59.
Rosenberg, H. I., and Richardson, K. C. (1995). Cephalic morphology of the honey possum, Tarsipes rostratus (Marsupialia: Tarsipedidae); An obligate nectarivore. J. Morphol. 223: 303–323.
Rougier, G. W. (1993). Vincelestes neuquenianus Bonaparte (Mammalia, Theria) un primitivo mamifero del Cretácico Inferior de la Cuenca Neuquina, Tesis doctoral, Universidad Nacional de Buenos Aires, Buenos Aires.
Rougier, G. W., Wible, J. R., and Hopson, J. A. (1996). Basicranial anatomy of Priacodon fruitaensis (Triconodontidae, Mammalia) from the late Jurassic of Colorado, and a reappraisal of mammaliaform interrelationships. Am. Mus. Novitates 3183: 1–38.
Saban, R. (1968). Musculature de la tête. In: Traité de Zoologie, P.-P. Grassé, ed., pp. 229–471, Masson et Cie Éditeurs, Paris.
Sánchez-Villagra, M. R., and Kay, R. F. (1995). A skull of Proargyrolagus, the oldest argyrolagid (early Miocene Salla Beds, Bolivia). J. Vert. Paleontol. 15: 51A–52A.
Sánchez-Villagra, M. R., and Kay, R. F. (1997). A skull of Proargyrolagus, the oldest argyrolagid (Late Oligocene Salla Beds, Bolivia), with brief comments concerning its paleobiology. J. Vert. Paleontol. (in press).
Schumacher, G. H. (1961). Funktionelle Morphologie der Kaumuskulatur. Veb, Gustav Fischer Verlag, Jena.
Seebeck, J. H., Bennett, A. F., and Scotts, D. J. (1989). Ecology of the Potoroidae—A review. In: Kangaroos, Wallabies and Rat-Kangaroos, G. Grigg, P. Jarman, and I. Hume, eds., pp. 67–88, Surrey Beatty & Sons Pty. Ltd., New South Wales.
Simpson, G. G. (1926). Mesozoic Mammalia. IV. The multituberculates as living animals. Am. J. Sci. XI: 228–250.
Simpson, G. G. (1970). The Argyrolagidae, extinct South American marsupials. Bull. Mus. Comp. Zool. 139: 1–86.
Smith, A., and Hume, I. (eds.) (1984). Possums and Gliders, Australian Mammal Society, Sydney.
Smith, K. K. (1994). Development of craniofacial musculature in Monodelphis domestica (Marsupialia, Didelphidae). J. Morphol. 222: 149–173.
Springer, M. S., Kirsch, J. A. W., Aplin, K., and Flannery, T. (1990). DNA hybridization, cladistics, and the phylogeny of phalangerid marsupials. J. Mol. Evol. 30: 298–311.
Springer, M. S., McKay, G., Aplin, K. and Kirsch, J. A. W. (1992). Relationships among ringtail possums (Marsupialia: Pseudocheiridae) based on DNA-DNA hybridisation. Aust. J. Zool. 40: 423–435.
Springer, M. S., Westerman, M., and Kirsch, J. A. W. (1994). Relationships among orders and families of marsupials based on 12S ribosomal DNA sequences and the timing of the marsupial radiation. J. Mammal. Evol. 2: 85–115.
Strahan, R., (ed). (1995). Mammals of Australia, Smithsonian Institution Press, Washington, DC.
Szalay, F. S. (1994). Evolutionary History of the Marsupials and an Analysis of Osteological Characters, Cambridge University Press, New York.
Szalay, F. S., and Trofimov, B. A. (1996). The Mongolian Late Cretaceous Asiatherium, and the early phylogeny and paleobiogeography of Metatheria. J. Vert. Paleontol. 16: 474–509.
Tate, G. H. H. (1948). Results of the Archbold Expeditions No. 59. Studies on the anatomy and phylogeny of the Macropodidae (Marsupialia). Bull. Am. Mus. Nat. Hist. 91: 233–352.
Tedford, R. H., and Woodburne, M. O. (1987). The Ilariidae, a new family of vombatiform marsupials from the Miocene strata of South Australia and an evaluation of the homology of molar cusps in the Diprotodontia. In: Possums and Opossums: Studies in Evolution, M. Archer, ed., pp. 401–18, Surrey Beatty and Sons and the Royal Zoological Society of New South Wales, Sydney.
Thomas, O. (1888). Catalogue of the Marsupialia and Monotremata in the Collection of the British Museum, British Museum, Nat. Hist., London.
Thompson, S. D. (1987). Body size, duration of parental care, and the intrinsic rate of natural increase in eutherian and metatherian mammals. Oecologia 71: 201–209.
Turnbull, W. D. (1970). Mammalian masticatory apparatus. Fieldiana Geol. 18: 149–356.
Tyndale-Biscoe, H., and Renfree, M. (1987). Reproductive Physiology of Marsupials, Cambridge University Press, Cambridge.
von Koenigswald, W., and Storch, G. (1992). The marsupials: Inconspicuous opossums. In: Messel. An Insight into the History of Life and of the Earth, S. Schaal and W. Ziegler, eds., pp. 155–158, Clarendon Press, Oxford.
Wake, D. B., and Roth, G. (1989). The linkage between ontogeny and phylogeny in the evolution of complex systems. In: Complex Organismal Functions: Integration and Evolution in Vertebrates, D. B. Wake and G. Roth, eds., pp. 361–377, Wiley, Chichester.
Wall, C. E., and Krause, D. W. (1992). A biomechanical analysis of the masticatory apparatus of Ptilodus (Multituberculata). J. Vert. Paleontol. 12: 172–187.
Wilson, D. E., and Reeder, D. M., (eds.) (1993). Mammal Species of the World, 2nd ed., Smithsonian Institution Press, Washington, DC.
Winge, H. (1941). The Interrelationships of the Mammalian Genera. Vol I. Monotremata, Marsupialia, Insectivora, Chiroptera, Edentata, C. A. Reitzels Forlag, Copenhagen.
Wood Jones, F. (1923). The Mammals of South Australia. Part I. The Monotremes and the Carnivorous Marsupials, E. E. Rogers, Adelaide.
Zeller, U. (1989). Die Entwicklung und Morphologie des Schädels von Ornitorhynchus anatinus (Mammalia: Prototheria: Monotremata). Abh. Senckenberg. Naturforsch. Ges. 545: 1–156.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sánchez-Villagra, M.R., Smith, K.K. Diversity and Evolution of the Marsupial Mandibular Angular Process. Journal of Mammalian Evolution 4, 119–144 (1997). https://doi.org/10.1023/A:1027318213347
Issue Date:
DOI: https://doi.org/10.1023/A:1027318213347