Cranial evidence for the presence of a second endemic elephant species on Cyprus
TL;DR: A skull recently excavated in the coastal area of Xylophagou, SE Cyprus, provides evidence that, indeed, two elephant species have existed on the island, and may have descended from or evolved as a result of a separate, more recent colonisation event.
About: This article is published in Quaternary International.The article was published on 2015-08-27. It has received 16 citations till now. The article focuses on the topics: Palaeoloxodon & Palaeoloxodon falconeri.
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TL;DR: Submitted abstracts should clearly state the purpose, brief statement of procedure, results and conclusions, and include the name, full address and topic on all submissions.
Abstract: s should clearly state the purpose, brief statement of procedure, results and conclusions. Please include your name, full address and topic on all submissions. At least one author of each abstract should register for the conference. All accepted abstracts will be published as symposium proceedings. Additionally, commended abstracts may be published in a journal after they are expanded to a manuscript followed by extensive reviewing. The language of the conference will be English.
577 citations
TL;DR: The results support the generality of the island rule in the sense that all but one of the elephants experienced dwarfism on islands, and found no support for the hypothesis that body size of elephants declines with island isolation.
Abstract: Aim
We investigated the hypothesis that insular body size of fossil elephants is directly related to isolation and surface area of the focal islands.
Location
Palaeo-islands worldwide.
Methods
We assembled data on the geographical characteristics (area and isolation) of islands and body size evolution of palaeo-insular species for 22 insular species of fossil elephants across 17 islands.
Results
Our results support the generality of the island rule in the sense that all but one of the elephants experienced dwarfism on islands. The smallest islands generally harbour the smallest elephants. We found no support for the hypothesis that body size of elephants declines with island isolation. Body size is weakly and positively correlated with island area for proboscideans as a whole, but more strongly correlated for Stegodontidae when considered separately. Average body size decrease is much higher when competitors are present.
Main conclusions
Body size in insular elephants is not significantly correlated with the isolation of an island. Surface area, however, is a significant predictor of body size. The correlation is positive but relatively weak; c. 23% of the variation is explained by surface area. Body size variation seems most strongly influenced by ecological interactions with competitors, possibly followed by time in isolation. Elephants exhibited far more extreme cases of dwarfism than extant insular mammals, which is consistent with the substantially more extended period of deep geological time that the selective pressures could act on these insular populations.
40 citations
Cites background from "Cranial evidence for the presence o..."
...This also applies to the significantly larger elephant species (P. xylophagou) of Cyprus (Athanassiou et al., 2014, 2015)....
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...The most pronounced case of size reduction is exhibited by P. falconeri (Sicily; Si = 0.02) and P. cypriotes (Cyprus; Si = 0.02) for Palaeoloxodon, M. creticus (Crete; Si = 0.04) for Mammuthus and S. sumbaensis (Sumba; Si = 0.08) for Stegodon....
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TL;DR: It is suggested that a tightly constrained growth trajectory, without major anatomical reorganization of the skull, allowed for flexible adaptations to changing environments and was one of the factors underlying the evolutionary success of insular dwarf elephants.
Abstract: Members of the mammalian families Elephantidae and Hippopotamidae (extant and extinct elephants and hippos) include extinct dwarf species that display up to 98% decrease in body size compared to probable ancestral sources. In addition to differences in body mass, skulls of these species consistently display distinctive morphological changes, including major reduction of pneumatised areas in dwarf elephants and shortened muzzles in dwarf hippos. Here we build on previous studies of island dwarf species by conducting a geometric morphometric analysis of skull morphology and allometry in target taxa, living and extinct, and elaborate on the relation between skull size and body size. Our analysis indicates that skull size and body size within terrestrial placental mammals scale almost isometrically (PGLS major axis slope 0.906). Furthermore, skull shape in dwarf species differed from both their ancestors and the juveniles of extant species. In insular dwarf hippos, the skull was subject to considerable anatomical reorganisation in response to distinct selection pressures affecting early ontogeny (the “island syndrome”). By contrast, skull shape in adult insular dwarf elephants can be explained well by allometric effects; selection on size may thus have been the main driver of skull shape in dwarf elephants. We suggest that a tightly constrained growth trajectory, without major anatomical reorganization of the skull, allowed for flexible adaptations to changing environments and was one of the factors underlying the evolutionary success of insular dwarf elephants.
21 citations
TL;DR: In this paper, it was shown that there exists a threshold of about 6-10 km distance between the island and the mainland, below which no dwarfism evolved, likely as a result of genetic contact with the mainland population.
15 citations
TL;DR: This article investigated the relationship between extinctions of insular endemic mammal species and their body mass, the size of the island and the first human arrival to the archipelago and found that megafauna was hit hard indeed.
12 citations
References
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01 Jan 1973
3,106 citations
"Cranial evidence for the presence o..." refers background in this paper
...Mediterranean islands are famous in biogeography as a prime example of the “Island Rule”, according to which an animal's size is affected as an adaptation to the peculiar ecological conditions of the insular environment (Van Valen, 1973)....
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TL;DR: GTS2012 as mentioned in this paper summarizes the international divisions and ages in the Geologic Time Scale, published in 2012, since 2004, when GTS2004 was detailed, major developments have taken place that directly bear and have considerable impact on the intricate science of geologic time scaling.
Abstract: This report summarizes the international divisions and ages in the Geologic Time Scale, published
in 2012 (GTS2012). Since 2004, when GTS2004 was detailed, major developments have taken place
that directly bear and have considerable impact on the intricate science of geologic time scaling. Precam brian
now has a detailed proposal for chronostratigraphic subdivision instead of an outdated and abstract chronometric
one. Of 100 chronostratigraphic units in the Phanerozoic 63 now have formal definitions, but stable
chronostratigraphy in part of upper Paleozoic, Triassic and Middle Jurassic/Lower Cretaceous is still wanting.
Detailed age calibration now exist between radiometric methods and orbital tuning, making 40Ar-39Ar dates
0.64% older and more accurate. In general, numeric uncertainty in the time scale, although complex and not
entirely amenable to objective analysis, is improved and reduced. Bases of Paleozoic, Mesozoic and Cenozoic
are bracketed by analytically precise ages, respectively 541 0.63, 252.16 0.5, and 65.95 0.05 Ma.
High-resolution, direct age-dates now exist for base-Carboniferous, base-Permian, base-Jurassic, base-Cenomanian
and base-Eocene. Relative to GTS2004, 26 of 100 time scale boundaries have changed age, of which
14 have changed more than 4 Ma, and 4 (in Middle to Late Triassic) between 6 and 12 Ma. There is much
higher stratigraphic resolution in Late Carboniferous, Jurassic, Cretaceous and Paleogene, and improved integration
with stable isotopes stratigraphy. Cenozoic and Cretaceous have a refined magneto-biochronology.
The spectacular outcrop sections for the Rosello Composite in Sicily, Italy and at Zumaia, Basque Province,
Spain encompass the Global Boundary Stratotype Sections and Points for two Pliocene and two Paleocene
stages. Since the cycle record indicates, to the best of our knowledge that the stages sediment fill is stratigraphically
complete, these sections also may fulfill the important role of stage unit stratotypes for three of
these stages, Piacenzian, Zanclean and Danian
1,892 citations
"Cranial evidence for the presence o..." refers methods in this paper
...…Spectrometry method), Akrotíri-Aet okremnos is dated to 11,504e12,096 calibrated years BP with a 2s uncertainty (Wigand and Simmons, in Simmons and associates, 1999; Simmons, 2014), that is at about the Pleistocene/Holocene boundary (currently set at 11.65 ka, Gradstein et al., 2012, chapter 30.7)....
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829 citations
TL;DR: Submitted abstracts should clearly state the purpose, brief statement of procedure, results and conclusions, and include the name, full address and topic on all submissions.
Abstract: s should clearly state the purpose, brief statement of procedure, results and conclusions. Please include your name, full address and topic on all submissions. At least one author of each abstract should register for the conference. All accepted abstracts will be published as symposium proceedings. Additionally, commended abstracts may be published in a journal after they are expanded to a manuscript followed by extensive reviewing. The language of the conference will be English.
577 citations
Book•
01 Jan 1973
494 citations
"Cranial evidence for the presence o..." refers background or methods in this paper
...antiquus in particular) the high and narrow molars, the rostrally diverging tusk alveoli, the flat or slightly concave frontal area and the very wide frontoparietal region (Osborn, 1942; Maglio, 1973)....
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...The dental measurements were taken according to the methodology proposed in the reference publication of Maglio (1973)....
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...1, precludes a connection to Mammuthus, whose cranial morphology is well known from numerous specimens (Osborn, 1942; Maglio, 1973; Lister, 1996a)....
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...…as that observed in the Siculo-Maltese dwarf elephant species P. falconeri and P. mnaidriensis sensu stricto. b) The metrical range reported for the mainland P. antiquus, sampled from various localities across Europe and various stratigraphic levels, is smaller (Table 2; see also Maglio, 1973, tab....
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...The absence of a domed cranial roof, as well as of parallel and closely spaced tusk alveoli in XY.05.1, precludes a connection to Mammuthus, whose cranial morphology is well known from numerous specimens (Osborn, 1942; Maglio, 1973; Lister, 1996a)....
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