Andrzej Elżanowski is a Polish

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

 paleontologist and vertebrate zoologist specializing in bird phylogeny. Together with Peter Wellnhofer

Peter Wellnhofer

Peter Wellnhofer is a German paleontologist at the "Bayerische Staatssammlung fur Paläontologie" in Munich. He is best known for his work on the various fossil specimens of Archaeopteryx or "Urvogel", the first known bird...

 he described a coelurosaur

Coelurosauria

Coelurosauria is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. In the past, it was used to refer to all small theropods, although this classification has been abolished...

 theropod

Theropoda

Theropoda is both a suborder of bipedal saurischian dinosaurs, and a clade consisting of that suborder and its descendants . Dinosaurs belonging to the suborder theropoda were primarily carnivorous, although a number of theropod groups evolved herbivory, omnivory, and insectivory...

 Archaeornithoides

Archaeornithoides

Archaeornithoides is a genus of maniraptoriform theropod dinosaur. It was found in Late Cretaceous river sandstones of the Djadokhta Formation beds located in Bayn Dzak, Mongolia...

in 1992. He works also on Mesozoic

Mesozoic

The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...

 birds, especially Archaeopterygiformes – he is author of the chapter "Archaeopterygidae" in book edited by Luis Chiappe and Lawrence Witmer

Lawrence Witmer

Lawrence Witmer is an American paleontologist. He is a Professor of Anatomy and a Chang Ying-Chien Professor of Paleontology at the Department of Biomedical Sciences at the College of Osteopathic Medicine in Ohio University. Witmer is considered to be one of the world's foremost Armchair...

 entitled Mesozoic Birds: Above the Heads of Dinosaurs. In 2001 he determined that Solnhofen specimen of Archaeopteryx

Archaeopteryx

Archaeopteryx , sometimes referred to by its German name Urvogel , is a genus of theropod dinosaur that is closely related to birds. The name derives from the Ancient Greek meaning "ancient", and , meaning "feather" or "wing"...

represents new species and genus and coined new specific name – Wellnhoferia grandis

Wellnhoferia

Wellnhoferia is a genus of early prehistoric bird closely related to Archaeopteryx. It lived in what is now Germany, during the Late Jurassic. While Wellnhoferia was similar to Archaeopteryx, it had a shorter tail and its fourth toe was shorter than in Archaeopteryx...

– for it. He works now in the Institute of Zoology of the University of Wrocław.