Pseudoextinction

In a single lineage, when an old chronospecies (A) is judged to have changed into a new species (B) by anagenesis, the old species is deemed phyletically extinct.

Pseudoextinction (or phyletic extinction) of a species occurs when all members of the species are extinct, but members of a daughter species remain alive. The term pseudoextinction refers to the evolution of a species into a new form, with the resultant disappearance of the ancestral form. Pseudoextinction results in the relationship between ancestor and descendant still existing even though the ancestor species no longer exists.^[1]

The classic example is that of the non-avian dinosaurs.^[2] While the non-avian dinosaurs of the Mesozoic died out, their descendants, birds, live on today. Many other families of bird-like dinosaurs also died out as the heirs of the dinosaurs continued to evolve, but because birds continue to thrive in the world today their ancestors are only pseudoextinct.^[3]

^ Leighton, Lindsey R. (2009). "Taxon Characteristics That Promote Survivorship Through the Permian-triassic Interval: Transition from the Paleozoic to the Mesozoic Brachiopod Fauna". Paleobiology. 34: 65–79. doi:10.1666/06082.1. S2CID 86843206.
^ Newman, Mark (2003). Modeling Extinction. Oxford University Press. p. 102. ISBN 9780195159462.
^ Newman, Mark; Palmer, R. J. (2003). Modeling Extinction. Oxford University Press. p. 18. ISBN 978-0195159462.

[1] Leighton, Lindsey R. (2009). "Taxon Characteristics That Promote Survivorship Through the Permian-triassic Interval: Transition from the Paleozoic to the Mesozoic Brachiopod Fauna". Paleobiology. 34: 65–79. doi:10.1666/06082.1. S2CID 86843206.

[2] Newman, Mark (2003). Modeling Extinction. Oxford University Press. p. 102. ISBN 9780195159462.

[3] Newman, Mark; Palmer, R. J. (2003). Modeling Extinction. Oxford University Press. p. 18. ISBN 978-0195159462.

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