Bis zu 50 % günstiger als neu 3 Jahre rebuy Garantie Professionelles Refurbishment

Handbook of Paleoherpetology / Thecodontia

Derzeit nicht verfügbar

Handgeprüfte Gebrauchtware

Bis zu 50 % günstiger als neu

Der Umwelt zuliebe

Handbook of Paleoherpetology / Thecodontia

Alan J Charig, Bernard Krebs, Hans D Sues, Frank Westphal (Broschiert, Deutsch, Englisch)

Keine Bewertungen vorhanden

Optischer Zustand

Beschreibung

Subclass ARCHOSAURIA COPE 1869 The Archosauria, the «ruling reptiles», represent one of the most important subclasses of the reptiles; they include not only the familiar crocodiles, but also the two separate dinosaur orders, the flying reptiles (pterosaurs) and the common ancestors of all these (thecodontians). All except the crocodilians have been extinct since Mesozoic times. When COPE first proposed the Archosauria, in 1869, he included all the forms just listed except the Pterosauria, which he regarded as an independent taxon of equivalent rank; but he included also three other very diverse groups (Sauropterygia, Anomodontia, Rhynchocephalia) which are now considered to have no close affinities either with the archosaurs or with each other. Difficult to define anatomically, the archosaurs in their modern sense nevertheless form a very distinct taxon which is not known at present to be connected with any other taxon by transitional genera. This taxon is usually regarded as a subclass, but a few authors have accorded it lower rank; indeed, COPE originally proposed it as an order, for he did not use subclasses. More recently, the Archosauria have sometimes been united with the Lepidosauria to form a common subclass Diapsida (even within the last decade, in such publications as COLBERT 1965b, CRUICKSHANK 1972), in which cases the Archosauria themselves are downgraded (to a superorder or an infraclass respectively). Most authorities, however, prefer to regard the connexion between lepidosaurs and archosaurs as not especially close, going no further than to include them all, together with the chelonians and the birds, in the rather loose grouping known as the «Sauropsida» (GoonRICH 1916, mentioned though not formally employed by ROMER 1956); this is based largely upon the arrangement of the aortic arches, which in all living reptiles is different from that of mammals. Others (e.g. ROMER 1968) doubt the existence of any connexion whatever between lepidosaurs and archosaurs. This raises the question of the origin of archosaurs, still shrouded in mystery. Those who use the term «diapsid» merely to denote a type of skull structure, e.g. ROMER 1966, 1968, 1971 d, suggest a direct and independent descent of the archosaurs from primitive captorhinomorph ancestors. On the other hand, those who consider «diapsid» to have phylogenetic implications postulate a common origin of both arcbosaurs and lepidosaurs through millerettids; this is perhaps the most conventional view. CRUICKSHANK, indeed, takes this further and suggests (1972) that the earliest archosaurs might be nothing more than slightly modified carnivorous rhynchocephalians, which, if true, would imply that both Archosauria and Lepidosauria had evolved from a common line of ancestry passing back through the Eosuchia to the Millerosauria. REIG has recently published (1967, 1970) an extremely unorthodox theory, argued in detail, which suggests that the archosaurs evolved in water from the ophiacodont-varanopid group of pelycosaurs; this, however, is strongly opposed by ROMER (1971d) and CRUICKSHANK (1972). Even more recent is a novel suggestion by CARROLL (in press) that the Archosauria are of diphyletic origin from the Eosuchia, with the Proterosuchia evolving independently of the rest. This theory is discussed in some detail later in the present work (pp. 12-13). The fact that there are living archosaurs, but not many, explains the inconsistency of the tenses used in this Introduction. Weniger zeigen

Dieses Produkt haben wir gerade leider nicht auf Lager.

ab 36,99 €

Derzeit nicht verfügbar

Handgeprüfte Gebrauchtware

Bis zu 50 % günstiger als neu

Der Umwelt zuliebe

Produktinformationen

Technische Daten

Erscheinungsdatum

18.08.1976

Sprache

Deutsch, Englisch

EAN

9783899370287

Herausgeber

Pfeil, F

Serien- oder Bandtitel

Handbook of Paleoherpetology

Sonderedition

Nein

Autor

Alan J Charig, Bernard Krebs, Hans D Sues, Frank Westphal

Seitenanzahl

137

Auflage

Einbandart

Broschiert

Warnhinweise und Sicherheitsinformationen

Informationen nach EU Data Act

Bewertungen

-.-

Leider noch keine Bewertungen

Sicher bei rebuy kaufen

Sehr Gut, 4.52/5.00

Aus 200.000+ Bewertungen

Schreib die erste Bewertung für dieses Produkt!

Wenn du eine Bewertung für dieses Produkt schreibst, hilfst du allen Kund:innen, die noch überlegen, ob sie das Produkt kaufen wollen. Vielen Dank, dass du mitmachst!