In pursuit of early mammals

A multituberculate (Catopsbaatar) about to fall prey

to a dinosaur (Saurornithoides)

This fascinating book is the autobiography of the eminent paleontologist Zofia Kielan-Jaworowska and an introduction to the early history of mammals.

Her descriptions of the Polish-Mongolian expeditions in 1963-71 recount the daunting logistics of working in the Gobi Desert 1000 km from Ulaanbaatar and transporting back fossils weighing several tons. The excitement of the fossil hunt is apparent: "I turned the block over and was left speechless! I had in my hands an almost complete, beautifully preserved skull of a small dinosaur." With this as a starting point we follow Zofia Kielan-Jaworowska's subsequent career, which included eight years on the faculty of Oslo University. In 2002 she returned to Gobi with her grandaughter Zosia; ten years on Zosia checked the references for the current volume. 

The second half of the book focuses on the evolution of mammals. It is restricted to the crown group that includes the living monotremes, marsupials and placentals and extinct groups with which they share a common ancestor. Arguably this includes the fossils of greatest interest to the general reader. For a more comprehensive treatment of the subject there is Mammals from the Age of Dinosaurs (2004) by Kielan-Jaworowska, Cifelli and Luo.

The new book contains potted biographies of many eminent vertebrate paleontologists, including some of the author's predecessors as well as recent stars such as Zhe-Xi Luo. It is richly illustrated with historical photos and line drawings of fossil mammals from the age of dinosaurs.

The spiny mouse

Spiny mouse (Acomys sp.) Wikimedia Commons

Despite its appearance the spiny mouse belongs to a different subfamily than the laboratory mouse. More importantly, it has a different reproductive strategy. Litter size is smaller and much of organ development occurs in utero resulting in the birth of precocial young. Thus it is a better model for late gestation in humans than the mouse, which has large litters and altricial young (see previous post).

At the same time, the laboratory species (Acomys cahirinus) is sufficiently close to mouse and rat that it is possible to develop primers based on the nucleotide sequences of mouse and rat genes (exemplified here). 

A group at Monash University has been using the spiny mouse in studies of fetal programming and sex-dependent effects of glucocorticoids on placental development (here). The spiny mouse holds great promise as a new model for placental and fetal development. Moreover, its potential for studies in a quite different area, tissue regeneration (here), means it is likely to be come more widely available as a laboratory animal.

Maureen Young 1915-2013



Maureen Young in Denmark 1989

Professor I. Maureen Young made an important contribution to our knowledge of amino acid transfer across the placenta and its role in fetal nutrition.

Maureen Young graduated from Bedford College for Women in 1938 and continued there as a demonstrator and assistant lecturer. During the Second World War the College evacuated to Cambridge where Maureen met Sir Joseph Barcroft. This was the start of a life long interest in fetal physiology (see her review of Barcroft's book here). In 1946 she moved to St. Thomas's Hospital Medical School. She was Professor of Perinatal Physiology there from 1976 until her retirement in 1982. She then settled at Toft in Cambridge.

Maureen was one of a generation of women who rose to the top in research often at great personal sacrifice. She wrote about some of the others in Women Physiologists (Portland Press 1993). At placenta meetings she was often to be found in the company of her American counterpart Elizabeth M. Ramsey (previous post).

Although international travel was eventually curtailed, Maureen continued to attend scientific meetings at Cambridge until well into her 95th year. She will be greatly missed.