Author Archives: LS

3D fossil scans available online

Hello dear Kurtenians!

Here are some great news that you may already be aware of, but here it is again:
A database of stereographic anaglyphs as well as full, printable, 3D models of over 20000 fossils observable in the British Isles has been made available online through a cooperation between the British Geological Survey, several musea in the UK and the Joint Information System Commitee.

http://www.3d-fossils.ac.uk/

Just fantastic!

—
Pierre

Fossilization causes organisms to appear erroneously primitive by distorting evolutionary trees

Rob Sansom gave a talk about this subject in last years SVPCA meeting, and we mentioned it in the BKK meeting afterwards. It was then ongoing, this is the results:

Fossilization causes organisms to appear erroneously primitive by distorting evolutionary trees

Robert S. Sansom & Matthew A. Wills

Fossils are vital for calibrating rates of molecular and morphological change through geological time, and are the only direct source of data documenting macroevolutionary transitions. Many evolutionary studies therefore require the robust phylogenetic placement of extinct organisms. Here, we demonstrate that the inevitable bias of the fossil record to preserve just hard, skeletal morphology systemically distorts phylogeny. Removal of soft part characters from 78 modern vertebrate and invertebrate morphological datasets resulted in significant changes to phylogenetic signal; it caused individual taxa to drift from their original position, predominately downward toward the root of their respective trees. This last bias could systematically inflate evolutionary rates inferred from molecular data because first fossil occurrences will not be recognised as such. Stem-ward slippage, whereby fundamental taphonomic biases cause fossils to be interpreted as erroneously primitive, is therefore a ubiquitous problem for all biologists attempting to infer macroevolutionary rates or sequences.

Scientific Reports 3, 2545  doi:10.1038/srep02545

http://www.nature.com/srep/2013/130829/srep02545/full/srep02545.html

 

__________________________________

Laura

Course on Mammalian diet evolution 23.9-3.12.2013

Welcome to a course on diet evolution in mammals.

– starts on Tuesday 23.9 12-14.00 in C108 (quota 15 students),

– maximum credits obtainable – 4: 2 credits for exam, 1 credit for essay, 1 cr for presence. Evaluation is based on the exam and/or the essay.

The course will describe the evolution of mammalian diets from early mammals to modern humans, adaptation of their teeth and digestive tracts to environment, and methods studying mammalian diet.

Several lectures will be focused on primate diets (monkeys, apes and early humans), dietary adaptations of early hominines (plant versus meat eaters) and the dietary changes in modern humans.

The first lectures will give an introduction to mammals, their teeth and digestive systems and their adaptation to environment (skull and teeth demonstration of the main features and basic differences among mammals).

 

Preliminary outline of lectures:

24.9 Lecture 1. Introduction to mammals, osteology

01.10 Lecture 2. Introduction to teeth, origin and morphology

08.10 Lecture 3. Demonstration, skulls, teeth

15.10 Lecture 4. Methods: teeth as proxy to environment: morphology (hypsodonty, crown type), structure (mesowear, microwear, GISWear), chemistry (isotope analysis)

29.10 Lecture 5. Diet and digestive system in mammals

05.11 Lecture 6. Early mammal diets, carnivory and carnivores

12.11 Lecture 7. Evolution of herbivory and herbivores, omnivory

19.11 Lecture 8. Primate diets, monkey, apes, early hominines

26.11 Lecture 9. Early humans’ changing environments, change in human diets over time

03.12 Lecture 10. Human subsistence and evolutionary nutrition (fossil versus modern)

 

— Diana

New and exciting course: Introduction to Statistical Paleobiology

Introduction to Statistical Paleobiology

Docent Lee Hsiang Liow, Centre for Ecological and Evolutionary Synthesis, University of Oslo

This master-level course is given by remote video except for the introductory and concluding lectures, for which Docent Liow will be physically present (in class room C108 in the Department of Geosciences and Geography, Physicum, Kumpula campus). The video lectures will be given in the video conference classroom Exactum A114.

The maximum attendance is 20. Please use Web Oodi to enroll.

Course outline:

Introductory Lecture (Sep 4 2013)
Introduce statistical paleobiology
Aims of course
Outline of lectures and assignments and introduction to first assignment

Lecture:

‐questions we ask in paleobiology
‐ the interconnectivity among biology, paleontology, geology and climate science
‐history of “quantitative paleobiology”
‐important figures
‐why quantification is important
‐what are models and why there are differences between mathematical and statistical models
‐the importance of models (and comparison to hypothesis testing)
‐why bother with confidence intervals (an illustration)

Lecture 1 (9 Sep Oslo)

Estimating extinction‐ singe taxa

Lecture 2 (11 Sep Oslo)

Estimating extinction‐ rates and “events”

Lecture 3 (16 Sep Oslo)

Phenotypic evolution – single lineages

Lecture 4 (18 Sep Oslo)

Phenotypic evolution – clades
Other possibilities: diversification (comparing paleo and phylo)
More CMR (a bit in Lecture 2)

Conclusion Lecture (2 Oct Helsinki)

Writing assignment
Writing a Wikipedia entry for a selected narrow paleobiology theme (non quantitative)

Each lecture will have associated R exercises

-MF

Mid Jurassic Mystery Mammal Solved – Or Not!

You wait since 1997 for another haramiyid to come along, then you get two in the same issue of Nature!:

A new arboreal haramiyid shows the diversity of crown mammals in the Jurassic period

Xiaoting Zheng, Shundong Bi, Xiaoli Wang & Jin Meng

Nature, Vol. 500, No. 7461. (8 August 2013), pp. 199-202,

doi:10.1038/nature12353

http://www.nature.com/nature/journal/v500/n7461/full/nature12353.html

A major unsolved problem in mammalian evolution is the origin of Allotheria, including Multituberculata and Haramiyida1–5. Multituber- culates are the most diverse and best known Mesozoic era mammals and ecologically resemble rodents, but haramiyids are known mainly from isolated teeth, hampering our search for their phylogenetic relationships. Here we report a new haramiyid from the Jurassic period of China, which is, to our knowledge the largest reported so far. It has a novel dentition, a mandible resembling advanced multi- tuberculates and postcranial features adapted for arboreal life. Our phylogenetic analysis places Haramiyida within crown Mammalia, suggesting the origin of crown Mammalia in the Late Triassic period and diversification in the Jurassic, which contrasts other estimated divergence times of crown Mammalia6–8. The new haramiyid reveals additional mammalian features of the group, helps to identify other haramiyids represented by isolated teeth, and shows again that, regardless of various phylogenetic scenarios, a complex pattern of evolution involving many convergences and/or reversals existed in Mesozoic mammals.

– Ian

Another Mid Jurassic Mystery Mammal Solved!

A Jurassic mammaliaform and the earliest mammalian evolutionary adaptations

Chang-Fu Zhou, Shaoyuan Wu, Thomas Martin & Zhe-Xi Luo

–Nature: Vol. 500, #7461, pp. 163-167 [doi: 10.1038/nature12429]

http://www.nature.com/nature/journal/v500/n7461/full/nature12429.html

The earliest evolution of mammals and origins of mammalian features can be traced to the mammaliaforms of the Triassic and Jurassic periods that are extinct relatives to living mammals. Here we describe a new fossil from the Middle Jurassic that has a mandibular middle ear, a gradational transition of thoracolumbar vertebrae and primitive ankle features, but highly derived molars with a high crown and multiple roots that are partially fused. The upper molars have longitudinal cusp rows that occlude alternately with those of the lower molars. This specialization for masticating plants indicates that herbivory evolved among mammaliaforms, before the rise of crown mammals. The new species shares the distinctive dental features of the eleutherodontid clade, previously represented only by isolated teeth despite its extensive geographic distribution during the Jurassic.  This eleutherodontid was terrestrial and had ambulatory gaits, analogous to extant terrestrial mammals such as armadillos or rock hyrax. Its fur corroborates that mammalian integument had originated well before the common ancestor of living mammals.

– Ian