Author Archives: Karme

Kurtén Club 20.3.

Greetings.

Next Tuesday, Ian Corfe will give a talk about a paper that came out on Wednesday:

“Adaptive radiation of multituberculate mammals before the extinction of dinosaurs”

(Or as the Daily Mail in the UK entitled it:

“Revealed: the secret of the peaceful beaver-like mammals which lived alongside the
dinosaurs for 20 million years”)

Time & Location:
16.00, 20.3.2012, C108 Physicum

Welcome

—Anton

Gregory P. Wilson, Alistair R. Evans, Ian J. Corfe, Peter D. Smits, Mikael Fortelius &
Jukka Jernvall

Nature (2012) doi:10.1038/nature10880

The Cretaceous?Paleogene mass extinction approximately 66 million years ago is
conventionally thought to have been a turning point in mammalian evolution. Prior to that
event and for the first two-thirds of their evolutionary history, mammals were mostly
confined to roles as generalized, small-bodied, nocturnal insectivores, presumably under
selection pressures from dinosaurs. Release from these pressures, by extinction of
non-avian dinosaurs at the Cretaceous?Paleogene boundary, triggered ecological
diversification of mammals. Although recent individual fossil discoveries have shown that
some mammalian lineages diversified ecologically during the Mesozoic era5, comprehensive
ecological analyses of mammalian groups crossing the Cretaceous?Paleogene boundary are
lacking. Such analyses are needed because diversification analyses of living taxa allow
only indirect inferences of past ecosystems. Here we show that in arguably the most
evolutionarily successful clade of Mesozoic mammals, the Multituberculata, an adaptive
radiation began at least 20 million years before the extinction of non-avian dinosaurs
and continued across the Cretaceous?Paleogene boundary. Disparity in dental complexity,
which relates to the range of diets, rose sharply in step with generic richness and
disparity in body size. Moreover, maximum dental complexity and body size demonstrate an
adaptive shift towards increased herbivory. This dietary expansion tracked the ecological
rise of angiosperms and suggests that the resources that were available to
multituberculates were relatively unaffected by the Cretaceous?Paleogene mass extinction.
Taken together, our results indicate that mammals were able to take advantage of new
ecological opportunities in the Mesozoic and that at least some of these opportunities
persisted through the Cretaceous?Paleogene mass extinction. Similar broad-scale
ecomorphological inventories of other radiations may help to constrain the possible

Kurtén Club 6.3.

Dear all,

next Tuesday, Jukka Jernvall will give a talk about their new paper. The talk is titled

Making panda teeth.

Time & Loc.:
16.00, 6.3.2012, C108 Physicum

Welcome,
Allu

Kurtén Club 28.2.

Dear all,

tomorrow, Anton Äyräväinen will give a talk about

Overview of the Crocodyliforms of Bauru Group.

Time & Loc.:
16.00, 28.2.2012, B112 Physicum

Welcome,
Allu

Kurtén Club 21.2.

Dear all,

tomorrow, Juha Saarinen will give a talk about

Mesowear for elephants – tooth wear -based diet analysis method for Proboscidea.

Time & Loc.:
16.00, 21.2.2012, C108 Physicum

Welcome,
Allu

Kurtén Club 14.2.

Dear all,

tomorrow we will have a group meeting / conversation session.

If you have interesting articles that consider your or the groups work, feel free to bring them with you.

Time & Loc.:
16.00, 14.2.2012, B112 Physicum

Welcome,
Allu

Reminder: Guest lecture, Mammals from the Age of Dinosaurs, 8.2.2012 16.00

Reminder:

Dear All,

The Björn Kurtén Club is hosting a guest lecture

Mammals from the Age of Dinosaurs by

Thomas Martin

Steinmann-Institut für Geologie, Mineralogie und Paläontologie, Universität Bonn, Nussallee 8, 53115 Bonn, Germany

Mammals are the dominant vertebrates on land, having colonized almost all kinds of environments. The great mammalian radiation began after the extinction of the dinosaurs about 65 million years ago, and subsequently the modern diversity arose. However, the history of mammals started much earlier, some 200 million years ago in the Late Triassic, meaning two thirds of mammalian evolutionary history occurred in the Mesozoic, alongside the dinosaurs. The Jurassic is particularly important for mammalian evolution, with important key characters of modern mammals having evolved. Mammals are characterized by two highly complex sets of features which can be studied in both living and fossil species; tribosphenic molar teeth, with a grinding function in addition to the primitive piercing and cutting; and the inner ear, with a coiled cochlea and three middle ear bones. Recent work and new fossils have thrown up surprises in the evolution of both these features.
For a long time, Mesozoic mammals were regarded as small insectivorous animals without any particular specializations. Spectacularly preserved new fossil discoveries of basal/primitive mammals in the Jurassic have revealed striking body plans and lifestyles that were inconceivable a decade ago for early mammals. Castorocauda from Mongolia reveals the oldest fossilised fur and was perfectly adapted for swimming with a beaver-like, flattened tail covered by small horny scales and webbed hind feet. Volaticotherium was a climber with a gliding membrane like the modern sugar glider. Fruitafossor, from the U.S.A., was a burrower and had enamel-less peglike teeth, like those of living armadillos that feed on ants/termites. These highly specialized Jurassic mammals lived and became extinct during the Mesozoic. In contrast the direct ancestors of modern mammals, such as Henkelotherium from the Jurassic of Portugal, were more generalized. They survived extinction at the end of the Cretaceous and evolved into the spaces left by the dinosaurs.
Professor Thomas Martin’s lecture will explore this fascinating Jurassic mammalian world, weaving these new fossil discoveries with his work on the body plans and lifestyles, teeth, and inner ears of Jurassic mammals, and stories from his fieldwork across the globe. The exciting new fossils may be just a glimpse of what is to come, demonstrating that we stand at the threshold of a dramatic change in the picture of early mammalian evolutionary history.

Time and location:
8.2.2012 (Wed.), 16.00, E204, Physicum, Kumpula Campus

Welcome,
Aleksis Karme

Kurtén Club 7.2.

Dear all,

tomorrow, Julia Schultz will give a talk about

Occlusal surface analysis of dryolestoid molars (Mammalia, Cladotheria).

Abstract:

The “primary trigon” and trigonid of the pretribosphenic dryolestoid molars are arranged in a reversed triangular pattern of trigon and “primary trigonid”, which is shared with the more plesiomorphic symmetrodontans (Spalacotheriida). During the embrasure shearing process the lower molars fit into the embrasures between the upper molars. A buccally oriented guiding groove of the unicuspid talonid of dryolestids is homologous to the hypoflexid structure of the tribosphenic molar. In dryolestids the shearing surface of this hypoflexid structure has mainly shearing function with a crushing component. However, in tribosphenic molars the hypoflexid is more steeply inclined and less involved in occlusal contacts. Striation analysis and virtual simulation of the relative movements of the molars using the newly developed “Occlusal Fingerprint Analysis”-software demonstrate a functional difference of the dryolestid and the tribosphenic hypoflexid. In the dryolestid hypoflexid, shearing is the important function during the chewing cycle, when the paracone slides buccally along the guiding groove. The average angle of the striations related to the occlusal plane is steeper than the inclination of the guiding groove in the hypoflexid. This indicates that the lower molar moves in two phases into occlusion during the chewing cycle: an initial puncture-crushing phase and a subsequent shearing phase before full centric occlusion. A typical tribosphenic grinding phase after centric occlusion does not occur in dryolestids. During the evolution of the talonid basin, the shearing area of the hypoflexid was displaced buccally and rotated in mesial direction. In combination with the formation of the talonid basin a functional shift in the chewing cycle from shearing to grinding occurred and the hypoflexid lost its function as a main shearing area.

Recent publications:

Schultz, J.A. & Martin, T. (2011): Wear pattern and functional morphology of dryolestoid molars (Mammalia, Cladotheria). Paläontologische Zeitschrift 85 (3): 269-285.

Lazzari, V., Schultz, J.A., Tafforeau, P., Martin, T. (2010): Occlusal pattern in paulchoffatiid multituberculates and the evolution of cusp morphology in mammaliamorphs with rodent-like dentitions. Journal of Mammalian Evolution 17: 177-192.

Time & Loc.:
16.00, 7.2.2012, C108 Physicum

Welcome,
Allu

Guest lecture, Mammals from the Age of Dinosaurs, 8.2.2012 16.00

Dear All,

The Björn Kurtén Club is hosting a guest lecture

Mammals from the Age of Dinosaurs by

Thomas Martin

Steinmann-Institut für Geologie, Mineralogie und Paläontologie, Universität Bonn, Nussallee 8, 53115 Bonn, Germany

Mammals are the dominant vertebrates on land, having colonized almost all kinds of environments. The great mammalian radiation began after the extinction of the dinosaurs about 65 million years ago, and subsequently the modern diversity arose. However, the history of mammals started much earlier, some 200 million years ago in the Late Triassic, meaning two thirds of mammalian evolutionary history occurred in the Mesozoic, alongside the dinosaurs. The Jurassic is particularly important for mammalian evolution, with important key characters of modern mammals having evolved. Mammals are characterized by two highly complex sets of features which can be studied in both living and fossil species; tribosphenic molar teeth, with a grinding function in addition to the primitive piercing and cutting; and the inner ear, with a coiled cochlea and three middle ear bones. Recent work and new fossils have thrown up surprises in the evolution of both these features.
For a long time, Mesozoic mammals were regarded as small insectivorous animals without any particular specializations. Spectacularly preserved new fossil discoveries of basal/primitive mammals in the Jurassic have revealed striking body plans and lifestyles that were inconceivable a decade ago for early mammals. Castorocauda from Mongolia reveals the oldest fossilised fur and was perfectly adapted for swimming with a beaver-like, flattened tail covered by small horny scales and webbed hind feet. Volaticotherium was a climber with a gliding membrane like the modern sugar glider. Fruitafossor, from the U.S.A., was a burrower and had enamel-less peglike teeth, like those of living armadillos that feed on ants/termites. These highly specialized Jurassic mammals lived and became extinct during the Mesozoic. In contrast the direct ancestors of modern mammals, such as Henkelotherium from the Jurassic of Portugal, were more generalized. They survived extinction at the end of the Cretaceous and evolved into the spaces left by the dinosaurs.
Professor Thomas Martin’s lecture will explore this fascinating Jurassic mammalian world, weaving these new fossil discoveries with his work on the body plans and lifestyles, teeth, and inner ears of Jurassic mammals, and stories from his fieldwork across the globe. The exciting new fossils may be just a glimpse of what is to come, demonstrating that we stand at the threshold of a dramatic change in the picture of early mammalian evolutionary history.

Time and location:
8.2.2012 (Wed.), 16.00, E204, Physicum, Kumpula Campus

Welcome,
Aleksis Karme

Kurtén Club 31.1.

Dear all,

tomorrow, Ekaterina Petrova will give a talk about

How to describe the enigmatic tooth morphology of the rhinoceros Elasmotherium (Fischer, 1808) from the Late Pliocene – Middle Pleistocene of Eastern Europe?

Time & Loc.:
16.00, 31.1.2012, B112 Physicum

Welcome,
Allu