Tag Archives: Miocene

Geoscience seminar TODAY / Leena Sukselainen

Dear all,

The Geoscience Seminar TODAY is given by Leena Sukselainen. Leena works as a PhD student in our department and she is going to present us part of her thesis work.

Friday, 23.10.
Time: 14.15
Location: D114 Physicum, Kumpula Campus


All are welcome!



Both pliopithecoid and hominoid primates were widely distributed throughout Eurasia during the Miocene, but are known to have coexisted only at a few localities. It has been speculated that their different habitat preferences permitted only minimal overlap under special environmental conditions. Here, we study the context for pliopithecoid and hominoid co-occurrence by assessing taxonomically-based palaeoecological diversity of associated fossil mammals, as well as through direct ecometric analysis based on hypsodonty of mammalian herbivores. Our results show that pliopithecoids persistently inhabited more humid environments compared to other primate groups studied, suggesting an inability to adapt to changing environmental conditions. The opportunity for hominoids and pliopithecoids to co-occur appears to have been restricted by the niche conservatism in the latter group. Our study also indicates that direct ecometric analysis gives a better separation of the ecological preferences of these primate clades than do analyses of taxonomically-based community structure.


Oligo-Miocene climate change and mammal body-size evolution: a test of Bergmann’s Rule

Oligo-Miocene climate change and mammal body-size evolution in the northwest United States: a test of Bergmann’s Rule

John D. Orcutt and Samantha S. B. Hopkins

Paleobiology: Fall 2013, Vol. 39, No. 4, pp. 648-661.

Whether or not climate plays a causal role in mammal body-size evolution is one of the longest-standing debates in ecology. Bergmann’s Rule, the longest-standing modeladdressing this topic, posits that geographic body-mass patterns are driven by temperature, whereas subsequent research has suggested that other ecological variables, particularly precipitation and seasonality, may be the major drivers of body-size evolution. While paleoecological data provide a unique and crucial perspective on this debate, paleontological tests of Bergmann’s rule and its corollaries have been scarce. We present a study of body-size evolution in three ecologically distinct families of mammal (equids, canids, and sciurids) during the Oligo-Miocene of the northwest United States, an ideal natural laboratory for such studies because of its rich fossil and paleoclimatic records. Body-size trends are different in all three groups, and in no case is a significant relationship observed between body size and any climatic variable, counter to what has been observed in modern ecosystems. We suggest that for most of the Cenozoic, at least in the Northwest, body mass has not been driven by any one climatic factor but instead has been the product of complex interactions between organisms and their environments, though the nature of these interactions varies from taxon to taxon. The relationship that exists between climate and body size in many groups of modern mammals, therefore, is the exception to the rule and may be the product of an exceptionally cool and volatile global climate. As anthropogenic global warming continues and ushers in climatic conditions more comparable to earlier intervals of the Cenozoic than to the modern day, models of corresponding biotic variables such as body size may lose predictive power if they do not incorporate paleoecological data.



Updated chronology for the Miocene hominoid radiation in Western Eurasia

Isaac Casanovas-Vilar, David M. Alba, Miguel Garcés, Josep M. Robles, and Salvador Moyà-Solà
Published online before print March 21, 2011,
doi: 10.1073/pnas.1018562108

Extant apes (Primates: Hominoidea) are the relics of a group that was much more diverse in the past. They originated in Africa around the Oligocene/Miocene boundary, but by the beginning of the Middle Miocene they expanded their range into Eurasia, where they experienced a far-reaching evolutionary radiation. A Eurasian origin of the great ape and human clade (Hominidae) has been favored by several authors, but the assessment of this hypothesis has been hampered by the lack of accurate datings for many Western Eurasian hominoids. Here we provide an updated chronology that incorporates recently discovered Iberian taxa and further reevaluates the age of many previously known sites on the basis of local biostratigraphic scales and magnetostratigraphic data. Our results show that identifiable Eurasian kenyapithecins (Griphopithecus and Kenyapithecus) are much younger than previously thought (ca. 14 Ma instead of 16 Ma), which casts serious doubts on the attribution of the hominoid tooth from Engelswies (16.3–16.5 Ma) to cf. Griphopithecus. This evidence is further consistent with an alternative scenario, according to which the Eurasian pongines and African hominines might have independently evolved in their respective continents from similar kenyapithecin ancestors, resulting from an early Middle Miocene intercontinental range extension followed by vicariance. This hypothesis, which would imply an independent origin of orthogrady in pongines and hominines, deserves further testing by accurately inferring the phylogenetic position of European dryopithecins, which might be stem pongines rather than stem hominines.

Kurtén Club 19.10.

Dear all,

next tuesday, Ferhat Kaya will give a talk about

Sivas Upper Miocene Project, Sivas-Turkey.

Time & Loc.:
16.00, 19.10.2010, C108 Physicum

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Kurtén Club 27.4.

Dear all,

today, Majid Mirzaie Ataabadi will give a talk about

The Miocene of Western Asia; fossil mammals at the crossroad of faunal provinces and climate regimes

Time & Loc.:
16.00, 27.4.2010, C108 (Physicum)