Landlubbers to leviathans: evolution of swimming in mosasaurine mosasaurs
(2011) In Paleobiology 37(3). p.445-469- Abstract
- Incremental stages of major evolutionary transitions within a single animal lineage are rarely observed in the fossil record. However, the extraordinarily complete sequence of well preserved material spanning the 27-Myr existence of the marine squamate subfamily Mosasaurinae provides a unique exception. By comparison with extant and extinct analogs, the tail morphology of four mosasaurine genera is examined, revealing a pattern of evolution that begins with the generalized varanoid anatomy and culminates in a high-aspect-ratio fin, similar to that of sharks. However, unlike the epicercal caudal fluke of selachians in which the tail bends dorsocaudally, derived mosasaurs develop a hypocercal tail with a ventrocaudal bend. Progressive caudal... (More)
- Incremental stages of major evolutionary transitions within a single animal lineage are rarely observed in the fossil record. However, the extraordinarily complete sequence of well preserved material spanning the 27-Myr existence of the marine squamate subfamily Mosasaurinae provides a unique exception. By comparison with extant and extinct analogs, the tail morphology of four mosasaurine genera is examined, revealing a pattern of evolution that begins with the generalized varanoid anatomy and culminates in a high-aspect-ratio fin, similar to that of sharks. However, unlike the epicercal caudal fluke of selachians in which the tail bends dorsocaudally, derived mosasaurs develop a hypocercal tail with a ventrocaudal bend. Progressive caudal regionalization, reduced intervertebral mobility, increased tail depth due to a marked downturn of the posterior caudal segment, and the development of finlike paired appendages reveal a pattern of adaptation toward an optimized marine existence. This change in morphology reflects a transition from anguilliform or sub-carangiform locomotion to carangiform locomotion, and indicates a progressive shift from nearshore dwellers to pelagic cruisers-a change in foraging habitat independently corroborated by paleobiogeographic, stable isotope, osteohistological, and paleopathological data. Evolutionary patterns similar to those observed in mosasaurine mosasaurs are seen in other secondarily aquatically adapted ainniotes, notably metriorhynchid crocodyliforms, cetaceans, and ichthyosaurs, and may be explained by developmental modularity governing the observed phenotypic expression. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/2032226
- author
- Lindgren, Johan LU ; Polcyn, Michael J. and Young, Bruce A.
- organization
- publishing date
- 2011
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Paleobiology
- volume
- 37
- issue
- 3
- pages
- 445 - 469
- publisher
- Paleontological Soc Inc
- external identifiers
-
- wos:000292342200008
- scopus:79958727807
- ISSN
- 1938-5331
- DOI
- 10.1666/09023.1
- language
- English
- LU publication?
- yes
- id
- 245d3975-7603-42f1-8726-127228599721 (old id 2032226)
- date added to LUP
- 2016-04-01 10:08:50
- date last changed
- 2022-04-27 18:58:58
@article{245d3975-7603-42f1-8726-127228599721,
abstract = {{Incremental stages of major evolutionary transitions within a single animal lineage are rarely observed in the fossil record. However, the extraordinarily complete sequence of well preserved material spanning the 27-Myr existence of the marine squamate subfamily Mosasaurinae provides a unique exception. By comparison with extant and extinct analogs, the tail morphology of four mosasaurine genera is examined, revealing a pattern of evolution that begins with the generalized varanoid anatomy and culminates in a high-aspect-ratio fin, similar to that of sharks. However, unlike the epicercal caudal fluke of selachians in which the tail bends dorsocaudally, derived mosasaurs develop a hypocercal tail with a ventrocaudal bend. Progressive caudal regionalization, reduced intervertebral mobility, increased tail depth due to a marked downturn of the posterior caudal segment, and the development of finlike paired appendages reveal a pattern of adaptation toward an optimized marine existence. This change in morphology reflects a transition from anguilliform or sub-carangiform locomotion to carangiform locomotion, and indicates a progressive shift from nearshore dwellers to pelagic cruisers-a change in foraging habitat independently corroborated by paleobiogeographic, stable isotope, osteohistological, and paleopathological data. Evolutionary patterns similar to those observed in mosasaurine mosasaurs are seen in other secondarily aquatically adapted ainniotes, notably metriorhynchid crocodyliforms, cetaceans, and ichthyosaurs, and may be explained by developmental modularity governing the observed phenotypic expression.}},
author = {{Lindgren, Johan and Polcyn, Michael J. and Young, Bruce A.}},
issn = {{1938-5331}},
language = {{eng}},
number = {{3}},
pages = {{445--469}},
publisher = {{Paleontological Soc Inc}},
series = {{Paleobiology}},
title = {{Landlubbers to leviathans: evolution of swimming in mosasaurine mosasaurs}},
url = {{http://dx.doi.org/10.1666/09023.1}},
doi = {{10.1666/09023.1}},
volume = {{37}},
year = {{2011}},
}