| 1. |
- Andersson, Ki, 1975-
(författare)
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Aspects of locomotor evolution in the Carnivora (Mammalia)
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, the shape of the distal humerus trochlea is analysed using landmark-based morphometrics and multivariate methods, with the aim of exploring locomotor evolution in carnivorans. Elbow joint morphology is used together with body size and craniodental morphology to characterize past and present carnivorans. Evolutionary implications are studied at the ordinal, familial, and species levels, testing specific hypotheses about scaling, morphological constraints, evolutionary trajectories, and potential for social pack-hunting behaviour. The circumference of the distal humerus trochlea is found to be highly correlated with body mass, and appears to scale similarly throughout the order Carnivora. A general predictive model for carnivoran bodymass is presented (a=0.601; b= 2.552; r2=0.952, SEE=0.136, p<0001, n=92), which removes the need for the investigator to actively choose between the diverging estimates that different predictors and their equations often produce. At the elbow joint, manual manipulation and locomotion appear to be conflicting functions, thus suggesting mutually exclusive lifestyles involving either forelimb grappling or pursuit. At large body sizes, carnivorans are distributed over a strongly dichotomised pattern (grappling or locomotion), a pattern coinciding with the postulated threshold in predator-prey size ratio at 21.5-25 kg. This pattern is compared to that of two carnivoran faunas from the Tertiary. In the Oligocene (33.7-23.8 Myr BP), the overall pattern is remarkably similar to that observed for extant Carnivora. In the Miocene (23.8-11.2 Myr BP) carnivores show a similarly dichotomised pattern as the Oligocene and Recent, although the whole pattern is shifted towards larger body sizes. This difference is suggested to be a reflection of the extraordinary species richness of browsing ungulates in the early Miocene of North America. Such an increase in prey spectrum would create a unique situation, in which large carnivores need not commit to a cursorial habitus in order to fill their nutritional requirements. Finally, the elbow joints and craniodental morphology (14 measurements) of fossil canids were examined with the aim of assessing the potential for pack-hunting in fossil canids. It is clear that small and large members of the Recent Caninae share similar craniodental morphologies. However, this pattern is not present in Borophaginae and Hesperocyoninae. In the latter, large representatives are characterized by being short-faced, with reduced anterior premolars and enlarged posterior premolars, thus approaching a “pantherine-like” craniodental configuration. These traits are interpreted as an adaptation for killing prey with canine bites. It is similarly determined that, unlike recent Caninae, all analyzed species of borophagines and hesperocyonines have retained the ability to supinate their forearms. It is therefore likely that manual manipulation was part of their hunting behaviour, thus removing an essential part of the argument for social pack-hunting in these forms, as the benefits of such a strategy become less obvious.
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| 2. |
- Fortelius, Mikael, et al.
(författare)
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The Origin and Early History of NOW as It Happened
- 2023
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Ingår i: Evolution of Cenozoic Land Mammal Faunas and Ecosystems: 25 years of the NOW database of fossil mammals.. - : Springer. ; , s. 7-32
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Bokkapitel (refereegranskat)abstract
- The NOW database of fossil mammals came to be through a confluence of several initiatives spanning multiple decades. The first public version of NOW database was released in 1996 and the first Advisory Board was established the year after. Originally, NOW stood for Neogene of the Old World but with the gradual expansion of the database the acronym was eventually reassigned to stand for New and Old Worlds. The structure of what would become NOW was originally cloned from the ETE database of the Smithsonian Institution and the first NOW version accessible over the internet was a node of the ETE database. The first standalone, online version of NOW was launched in 2005 and the first formal steering group was established in 2009. During its existence, NOW has been funded, directly or indirectly, by several organizations but fundamentally it has always been an unfunded community effort, dependent on voluntary work by the participants.
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| 3. |
- Žliobaitė, Indrė, et al.
(författare)
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The NOW Database of Fossil Mammals
- 2023
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Ingår i: Evolution of Cenozoic Land Mammal Faunas and Ecosystems: 25 years of the NOW database of fossil mammals. - : Springer. ; , s. 33-42
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Bokkapitel (refereegranskat)abstract
- NOW (New and Old Worlds) is a global database of fossil mammal occurrences, currently containing around 68,000 locality-species entries. The database spans the last 66 million years, with its primary focus on the last 23 million years. Whereas the database contains records from all continents, the main focus and coverage of the database historically has been on Eurasia. The database includes primarily, but not exclusively, terrestrial mammals. It covers a large part of the currently known mammalian fossil record, focusing on classical and actively researched fossil localities. The database is managed in collaboration with an international advisory board of experts. Rather than a static archive, it emphasizes the continuous integration of new knowledge of the community, data curation, and consistency of scientific interpretations. The database records species occurrences at localities worldwide, as well as ecological characteristics of fossil species, geological contexts of localities and more. The NOW database is primarily used for two purposes: (1) queries about occurrences of particular taxa, their characteristics and properties of localities in the spirit of an encyclopedia; and (2) large scale research and quantitative analyses of evolutionary processes, patterns, reconstructing past environments, as well as interpreting evolutionary contexts. The data are fully open, no logging in or community membership is necessary for using the data for any purpose.
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| 4. |
- Adrian, Brent, et al.
(författare)
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New Miocene Carnivora (Mammalia) from Moruorot and Kalodirr, Kenya
- 2018
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Ingår i: Palaeontologia Electronica. - : Coquina Press. - 1935-3952 .- 1094-8074. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- We describe new carnivoran fossils from Kalodirr and Moruorot, two late EarlyMiocene sites in the Lothidok Formation of West Turkana, Kenya. The fossils include anew species of viverrid, Kichechia savagei sp. nov., a new genus and species of felid,Katifelis nightingalei gen. et sp. nov., and an unidentified musteloid. We also reportnew records of the amphicyonid Cynelos macrodon. These new fossils increase theknown diversity of African Early Miocene carnivorans and highlight regional differencesin Africa.
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| 5. |
- Alroy, John, et al.
(författare)
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The MN System: regional or continental?
- 1998
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Ingår i: Mitteilungen der Bayerischen Staatssammlung für Paläontologie und historische Geologie. ; 38, s. 243-258
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Andersson, Ki, et al.
(författare)
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Carnivora from the Late Miocene of Lantian, China
- 2005
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Ingår i: Vertebrata PalAsiatica. ; 43, s. 256-271
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Tidskriftsartikel (refereegranskat)abstract
- Sediments of the Bahe and Lantian formations, Lantian area, Shaanxi Province, China, have produced a large number of mammalian fossils. This Late Miocene sequence provides evidence for a period of major changes in the physical environment of the region. The carnivoran fossils are described and analyzed herein. The following species are present: lctitherium viverrinum, Hyaenictitherium cf . H. wongii and Adcrocuta eximia ( Hyaenidae) , cf. Metailurus major and cf. Metailurus parvulus ( Felidae) . Although a difference in the composition of the carnivoran fauna is noted towards the boundary between the Bahe Formation (lower) and Lantian Formation (upper), the cause of this is yet to be determined.
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| 7. |
- Andersson, Ki, et al.
(författare)
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Sabertoothed carnivores and the killing of large prey
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:10, s. e24971-
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Tidskriftsartikel (refereegranskat)abstract
- Sabre-like canines clearly have the potential to inflict grievous wounds leading to massive blood loss and rapid death. Hypotheses concerning sabretooth killing modes include attack to soft parts such as the belly or throat, where biting deep is essential to generate strikes reaching major blood vessels. Sabretoothed carnivorans are widely interpreted as hunters of larger and more powerful prey than that of their present-day nonsabretoothed relatives. However, the precise functional advantage of the sabretooth bite, particularly in relation to prey size, is unknown. Here, we present a new point-to-point bite model and show that, for sabretooths, depth of the killing bite decreases dramatically with increasing prey size. The extended gape of sabretooths only results in considerable increase in bite depth when biting into prey with a radius of less than ~10 cm. For sabretooths, this size-reversed functional advantage suggests predation on species within a similar size range to those attacked by present-day carnivorans, rather than “megaherbivores” as previously believed. The development of the sabretooth condition appears to represent a shift in function and killing behaviour, rather than one in predator-prey relations. Furthermore, our results demonstrate how sabretoothed carnivorans are likely to have evolved along a functionally continuous trajectory: beginning as an extension of a jaw-powered killing bite, as adopted by present-day pantherine cats, followed by neck-powered biting and thereafter shifting to neck-powered shear-biting. We anticipate this new insight to be a starting point for detailed study of the evolution of pathways that encompass extreme specialisation, for example, understanding how neck-powered biting shifts into shear-biting and its significance for predator-prey interactions. We also expect that our model for point-to-point biting and bite depth estimations will yield new insights into the behaviours of a broad range of extinct predators including therocephalians (gorgonopsian + cynodont, sabretoothed mammal-like reptiles), sauropterygians (marine reptiles) and theropod dinosaurs.
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