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The evolution of birds began in the Jurassic Period, with the earliest birds derived from a clade of theropod dinosaurs named Paraves. [1] Birds are categorized as a biological class, Aves. For more than a century, the small theropod dinosaur Archaeopteryx lithographica from the Late Jurassic period was considered to have been the earliest bird.
A turning point came in the early twentieth century with the writings of Gerhard Heilmann of Denmark.An artist by trade, Heilmann had a scholarly interest in birds and from 1913 to 1916, expanding on earlier work by Othenio Abel, [12] published the results of his research in several parts, dealing with the anatomy, embryology, behavior, paleontology, and evolution of birds. [13]
Xiphactinus, a large predatory fish, appears in the fossil record. 110 Ma First hesperornithes, toothed diving birds. Earliest limopsid, verticordiid, and thyasirid bivalves. 100 Ma First ants. [95] 100–95 Ma Spinosaurus appears in the fossil record. [96] 95 Ma First crocodilians evolve. [97] 90 Ma Extinction of ichthyosaurs.
Ichthyornis (meaning "fish bird", after its fish-like vertebrae) is an extinct genus of toothy seabird-like ornithuran from the late Cretaceous period of North America.Its fossil remains are known from the chalks of Alberta, Alabama, Kansas (Greenhorn Limestone), New Mexico, Saskatchewan, and Texas, in strata that were laid down in the Western Interior Seaway during the Turonian through ...
The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish lineages belong to the Agnatha, or jawless fish. Early examples include Haikouichthys.
A new study from the University of Adelaide looked at the DNA of this big guy, the elephant bird, one of the biggest birds to have ever existed. It lived on Madagascar and died out sometime in the ...
The evolution of tetrapods began about 400 million years ago in the Devonian Period with the earliest tetrapods evolved from lobe-finned fishes. [1] Tetrapods (under the apomorphy-based definition used on this page) are categorized as animals in the biological superclass Tetrapoda, which includes all living and extinct amphibians, reptiles, birds, and mammals.
Inside the stout fins of a fish that prowled the shallow waters of an estuary in what is now eastern Canada about 380 million years ago, scientists have found what they call the evolutionary ...