Author Archives: Mikko K Haaramo

New Romanian Cretaceous vertebrate site

An article about Romanian locations and Hateg Island

Mátyás Vremir, Ramona Balc, Zoltán Csiki-Sava, Stephen L. Brusatte, Gareth
Dyke, Darren Naish & Mark A. Norell (2014) Petresti-Arini
Cretaceous Research 49: 13-38


•Romania boasts some of the most unusual, insular dinosaurs in the fossil record.
•A new site preserves a unique late Campanian–earliest Maastrichtian fossil record.
•Dinosaurs and pterosaurs from this site are the oldest from the Haţeg Island.
•The Haţeg Island fauna was becoming established by the late Campanian.
•The site may suggest the earliest Haţeg faunas were somewhat distinct from later ones.

Evidence for a rapid release of carbon at the Paleocene-Eocene thermal maximum

Wright, J. D. & Schaller, M. F., 2013: Evidence for a rapid release of carbon at the Paleocene-Eocene thermal maximum.

–Proceedings of the National Academy of Sciences: Vol. 110, #40, pp. 15908- 15913 [doi: 10.1073/pnas.1309188110]


The Paleocene/Eocene thermal maximum (PETM) and associated carbon isotope excursion (CIE) are often touted as the best geologic analog for the current anthropogenic rise in pCO2. However, a causal mechanism for the PETM CIE remains unidentified because of large uncertainties in the duration of the CIE’s onset. Here, we report on a sequence of rhythmic sedimentary couplets comprising the Paleocene/Eocene Marlboro Clay (Salisbury Embayment). These couplets have corresponding δ18O cycles that imply a climatic origin. Seasonal insolation is the only regular climate cycle that can plausibly account for δ18O amplitudes and layer counts. High-resolution stable isotope records show 3.5‰ δ13C decrease over 13 couplets defining the CIE onset, which requires a large, instantaneous release of 13C-depleted carbon. During the CIE, a clear δ13C gradient developed on the shelf with the largest excursions in shallowest waters, indicating atmospheric δ13C decreased by ∼20‰. Our observations and revised release rate are consistent with an atmospheric perturbation of 3,000-gigatons of carbon (GtC).

Natural History of Vertebrates lecture-series 9.9.-14.10.2013

Welcome to the “Natural History of Vertebrates” lecture-series.

– starts on Monday, 9th of September (9.9.2013)
– lectures held in every  Monday and Friday at  10 – 12 in C108 (quota 15 students),
– maximum credits obtainable – 4: 2 credits for exam, 1 credit for essay,
1 cr for presence (70%). Evaluation is based on the exam and/or the essay.

Purpose of this lecture-series is to familiarize student to the 530 million year long vertebrate evolution history and its main events in the light of morphology, adaptations, and evolutionary perspective. Lecture-series second aim is to present numerous fossil vertebrate groups usually ignored in general teaching and in the prevailing scientific thinking. Familiarization with these groups allows open minds to draw interesting parallels with more familiar groups of vertebrates and their evolution.

Preliminary outline of lectures:

09.09. -13:        1. Origin of Vertebrates and Evolution of Jawless Vertebrates.

13.09.-13:         2. Origin and Evolution of Jawed Fishes.

16.09.-13:         3. Transfer to Land – Evolution of Amphibians.

20.09.-13:         4. Farewell to Water – Origin and Early Evolution of Amniotes.

23.09.-13:         5. Seamonsters – The Great Marine Amniotes of Mesozoic and Cenozoic Oceans.

27.09.-13:         6. Scaled Brotherhood – Mesozoic Small Reptiles.

30.09.-13:         7. Dragons of the Land – Evolution of Archosauria.

04.10.-13:         8. Dragons of the Air – Evolution of Flight on Vertebrates.

07.10.-13:         9. Ears, Whiskers and Milk – the Origin and Evolution of Synapsid Amniotes and Mesozoic Mammals.

11.10.-13:         10. Empire Established – Evolution of Therian Mammals from the Late Jurassic to the Present Day.

14.10.-13:         Examination

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

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:


Evolutionary origin of turtle shell

Tyler R. Lyson, Gabe S. Bever, Torsten M. Scheyer, Allison Y. Hsiang & Jacques

A. Gauthier (2013) Evolutionary Origin of the Turtle Shell.
Current Biology (advance online publication)

The origin of the turtle shell has perplexed biologists for more than two
centuries. It was not until Odontochelys semitestacea was discovered,
however, that the fossil and developmental data could be synthesized into
a model of shell assembly that makes predictions for the as-yet
unestablished history of the turtle stem group. We build on this model by
integrating novel data for Eunotosaurus africanus-a Late Guadalupian
(~260 mya) Permian reptile inferred to be an early stem turtle. Eunotosaurus
expresses a number of relevant characters, including a reduced number of
elongate trunk vertebrae (nine), nine pairs of T-shaped ribs, inferred loss of
intercostal muscles, reorganization of respiratory muscles to the ventral side
of the ribs, (sub)dermal outgrowth of bone from the developing perichondral
collar of the ribs, and paired gastralia that lack both lateral and median elements.
These features conform to the predicted sequence of character acquisition
and provide further support that E. africanus, O. semitestacea, and
Proganochelys quenstedti represent successive divergences from the turtle
stem lineage. The initial transformations of the model thus occurred by the Middle
Permian, which is congruent with molecular-based divergence estimates for the
lineage, and remain viable whether turtles originated inside or outside crown Diapsida.

Neonates and Embryos of Lufengosaurus

Are making waves in newsmedia… ☺

Reisz, R. R., Huang, T. D., Roberts, E. M., Peng, S., Sullivan, C., Stein, K., LeBlanc, A. R. H., Shieh, D., Chang, R., Chiang, C., Yang, C. & Zhong, S., 2013: Embryology of Early Jurassic dinosaur from China with evidence of preserved organic remains.
–Nature: Vol. 496, #7444, pp. 210-214 [doi: 10.1038/nature11978]


Fossil dinosaur embryos are surprisingly rare, being almost entirely restricted to Upper Cretaceous strata that record the late stages of non-avian dinosaur evolution. Notable exceptions are the oldest known embryos from the Early Jurassic South African sauropodomorph Massospondylus and Late Jurassic embryos of a theropod from Portugal. The fact that dinosaur embryos are rare and typically enclosed in eggshells limits their availability for tissue and cellular level investigations of development. Consequently, little is known about growth patterns in dinosaur embryos, even though post-hatching ontogeny has been studied in several taxa. Here we report the discovery of an embryonic dinosaur bone bed from the Lower Jurassic of China, the oldest such occurrence in the fossil record. The embryos are similar in geological age to those of Massospondylus and are also assignable to a sauropodomorph dinosaur, probably Lufengosaurus. The preservation of numerous disarticulated skeletal elements and eggshells in this monotaxic bone bed, representing different stages of incubation and therefore derived from different nests, provides opportunities for new investigations of dinosaur embryology in a clade noted for gigantism. For example, comparisons among embryonic femora of different sizes and developmental stages reveal a consistently rapid rate of growth throughout development, possibly indicating that short incubation times were characteristic of sauropodomorphs. In addition, asymmetric radial growth of the femoral shaft and rapid expansion of the fourth trochanter suggest that embryonic muscle activation played an important role in the pre-hatching ontogeny of these dinosaurs. This discovery also provides the oldest evidence of in situ preservation of complex organic remains in a terrestrial vertebrate.