Gerhard Heilmann

Gerhard Heilmann (1859–1946) was a Danish artist, paleontologist and writer of the "Origin of Birds", [cite book
last =Heilmann
first =Gerhard
authorlink =
title =The Origin of Birds
publisher =Witherby
date =1926
location =London
pages =209
isbn = ] an influential account of bird evolution.

Life

Heilmann was born in Skelskør, Denmark and studied medicine. In 1883, he abandoned medicine and became an artist's apprentice, later becoming a painter at the Royal Porcerlain Works in Copenhagen. He also designed Danish banknotes and became a book ilustrator.cite book
last =Chambers
first =Paul
authorlink =
coauthors =
title =Bones of Contention, the Fossil that Shook Science
publisher =John Maurray
date =2002
location =London
pages =270
url =
doi =
id =
isbn =0-7195-6059-4 ]

"The Origin of Birds"

Heilmann published a number of papers in Danish on the evolution of birds between 1913 and 1916, which were published in the "Journal of the Danish Ornithological Society" ("Dansk Ornitologisk Forenings Tidskrift" or DOFT). They were collected in 1916 as "Vor Nuværende Viden om Fuglenes Afstamning". He revised this and published it in English 1926 as the "The Origin of Birds". Like Thomas Huxley, Heilmann compared "Archaeopteryx" and other birds to an exhaustive list of prehistoric reptiles, and also came to the conclusion that theropod dinosaurs like "Compsognathus" were the most similar. However, Heilmann noted that birds possessed clavicles fused to form a bone called the furcula ('wishbone'), and while clavicles were known in more primitive reptiles, they had not yet been recognized in theropod dinosaurs. A firm believer in Dollo's Law, which states that evolution is not reversible, Heilmann could not accept that clavicles were lost in dinosaurs and re-evolved in birds, so he was forced to rule out dinosaurs as bird ancestors and ascribe all of their similarities to convergence. Heilmann stated that bird ancestors would instead be found among the more primitive 'thecodont' grade of reptiles. Heilmann's extremely thorough approach ensured that his book became a classic in the field and its conclusions on bird origins, as with most other topics, were accepted by nearly all evolutionary biologists for the next four decades,cite_book |last=Padian |first=Kevin. |year=2004 |chapter=Basal Avialae |editor=Weishampel, David B.; Dodson, Peter; & Osmólska, Halszka (eds.) |title=The Dinosauria |edition=Second Edition |location=Berkeley |publisher=University of California Press |pages=210-231 |isbn=0-520-24209-2] despite the discovery of clavicles in the primitive theropod "Segisaurus" in 1936.cite_journal |last=Camp |first=Charles L. |authorlink=Charles Lewis Camp |year=1936 |title=A new type of small theropod dinosaur from the Navajo Sandstone of Arizona |journal=Bulletin of the University of California Department of Geological Sciences |volume=24 |pages=39–65] Clavicles and even fully developed furculae have since been identified in numerous other non-avian dinosaurs.cite_journal |last=Chure |first=Daniel J. |coauthors=& Madsen, James H. |year=1996 |title=On the presence of furculae in some non-maniraptoran theropods |journal=Journal of Vertebrate Paleontology |volume=16 |issue=3 |pages=573–577] cite_journal |last=Norell |first=Mark A. |coauthors=& Makovicky, Peter J. |year=1999 |title=Important features of the dromaeosaurid skeleton II: Information from newly collected specimens of "Velociraptor mongoliensis" |journal=American Museum Novitates |volume=3282 |pages=1–44 |url=http://hdl.handle.net/2246/3025]

In 1940, Heilmann published a successful book on Darwinian evolution, the "Univers og traditionen" ("Universe and Tradition", in Danish).

Notes

Further reading

* [http://www.archaeopteryx.nl/heilmann/ Gerhard Heilmann] at archaeopteryx.nl