Model to generate phylogenetic missing stages of dinosaurs

Aim of the paper is to present a mathematical method used to generate the missing stages of the evolution of fossil vertebrates. Considered excavations may be in the form of skeletons or the traces left by autopodium during locomotion of these animals. The research material contains selected dinosaurs, which features of locomotor apparatus were described in terms of chronology and habitat affiliation. They were formalized in the form of a numeric code by Sikorska-Piwowska [Z. Sikorska-Piwowska. Modele biologique de l’´evolution de l’appareil locomoteur des tetrapodes. Zoologica Poloniae, 31(1-4), 1984.]. The present paper has in view taking into account the adaptation and specialization traits of limbs and also the types of autopodium joints and basipodium specializations. The vector of binary features is assigned to each investigated form of Tetrapoda. It was taken the simplified assumption of statistical independence and equipoise of investigated features during the building of the model. There are no reasons for distinguishing any of them. The projection of the spatial image of dinosaurs’ locomotor apparatus development has the expression in the form of mathematical cladogram. This model verifies some evolution stages like origin of pre-birds lined with hypothetic form related with Coelophysis, one of the earliest known dinosaurs from upper Triassic.

Aim of the paper is to present a mathematical method used to generate the missing stages of the evolution of fossil vertebrates. Considered excavations may be in the form of skeletons or the traces left by autopodium during locomotion of these animals. The research material contains selected dinosaurs, which features of locomotor apparatus were described in terms of chronology and habitat affiliation. They were formalized in the form of a numeric code by Sikorska-Piwowska [29]. The present paper has in view taking into account the adaptation and specialization traits of limbs and also the types of autopodium joints and basipodium specializations. The vector of binary features is assigned to each investigated form of Tetrapoda. It was taken the simplified assumption of statistical independence and equipoise of investigated features during the building of the model. There are no reasons for distinguishing any of them. The projection of the spatial image of dinosaurs’ locomotor apparatus development has the expression in the form of mathematical cladogram. This model verifies some evolution stages like origin of pre-birds lined with hypothetic form related with Coelophysis, one of the earliest known dinosaurs from upper Triassic. In such a manner Archeopteryx was left out from considerations as the ancestor of prebirds.