Tag Archives: Jurassic

Comments on Jurassic World in IltaSanomat by Maija & Mikko (in Finnish)

All,

Maija Karala and I gave a little interview and opinions to IltaSanomat of the Jurassic World.

Unfortunately it’s is only in Finnish.

http://www.istv.fi/viihde/vid-1435047061124.html

Those who haven’t yet watched the trailers, do so, it helps to understand some comments.

http://www.jurassicworldmovie.com/#

http://www.jurassicworld.com

–Mikko H.

More:
http://www.iltasanomat.fi/elokuvat/art-1435194630387.html

-Allu

New Late Jurassic docodontan

New Late Jurassic docodontan fossil (with skull) published in Science.

Evolutionary development in basal mammaliaforms as revealed by a docodontan

Zhe-Xi Luo1,*, Qing-Jin Meng2,*, Qiang Ji3, Di Liu2, Yu-Guang
Zhang2, April I. Neander1

A new Late Jurassic docodontan shows specializations for a
subterranean lifestyle. It is similar to extant subterranean golden
moles in having reduced digit segments as compared to the ancestral
phalangeal pattern of mammaliaforms and extant mammals. The reduction
of digit segments can occur in mammals by fusion of the proximal and
intermediate phalangeal precursors, a developmental process for which
a gene and signaling network have been characterized in mouse and
human. Docodontans show a positional shift of thoracolumbar ribs, a
developmental variation that is controlled by Hox9 and Myf5 genes in
extant mammals. We argue that these morphogenetic mechanisms of modern
mammals were operating before the rise of modern mammals, driving the
morphological disparity in the earliest mammaliaform diversification.

BR,
Nicolas

*********************************

Hi,

Actually not just one, but two new docodonts were published side by side.

One subterrestrial, which you are referring and one scansorial…

Luo, Z.-X., Meng, Q.-J., Ji, Q., Liu, D., Zhang, Y.-G. & Neander, A. I., 2015: Evolutionary development in basal mammaliaforms as revealed by a docodontan.
–Science: Vol. 347, #6223, pp. 760-764 [doi: 10.1126/science.1260880] http://dx.doi.org/10.1126/science.1260880

Meng, Q.-J., Ji, Q., Zhang, Y.-G., Liu, D., Grossnickle, D. M. & Luo, Z.-X., 2015: An arboreal docodont from the Jurassic and mammaliaform ecological diversification.
–Science: Vol. 347, #6223, pp. 764-768 [doi: 10.1126/science.1260879] http://dx.doi.org/10.1126/science.1260879

Cheers!

–Mikko H.

Rugosodon, earliest multituberculate mammal from Jurassic of China

A new paper in Science, describing Rugosodon. The Supplementary Materials are free.

Chong-Xi Yuan, Qiang Ji, Qing-Jin Meng, Alan R. Tabrum & Zhe-Xi Luo
(2013) Earliest Evolution of Multituberculate Mammals Revealed by a
New Jurassic Fossil Science 341 (6147): 779-783
DOI: 10.1126/science.1237970
http://www.sciencemag.org/content/341/6147/779

Multituberculates were successful herbivorous mammals and were more diverse and numerically abundant than any other mammal groups in Mesozoic ecosystems. The clade also developed diverse locomotor adaptations in the Cretaceous and Paleogene. We report a new fossil skeleton from the Late Jurassic of China that belongs to the basalmost multituberculate family. Dental features of this new Jurassic multituberculate show omnivorous adaptation, and its well-preserved skeleton sheds light on ancestral skeletal features of all multituberculates, especially the highly mobile joints of the ankle, crucial for later evolutionary success of multituberculates in the Cretaceous and Paleogene.

Lots of news stories:

http://www.nature.com/news/fossil-reveals-features-of-mammal-line-that-outlived-dinosaurs-1.13568

http://news.nationalgeographic.com/news/2013/08/130815-multituberculate-rugosodon-early-mammal-evolution/

http://www.livescience.com/38924-ancient-rodentlike-creature-discovered.html

 

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