First trace and body fossil evidence of a burrowing, denning dinosaur

When did arthropods first invade the land? Circumstantial evidence based on trace fossils (Retallack and Feakes, 1987) suggests that large animals, possibly arthropods, may have been present on land and burrowing in soils in the Late Ordovician, but this idea is as yet unsupported by body fossil evidence.

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Asymmetry in the fossil record

European Review ◽

10.1017/s1062798705000712 ◽

2005 ◽

Vol 13 (S2) ◽

pp. 135-143 ◽

Cited By ~ 17

Author(s):

LOREN E. BABCOCK

Keyword(s):

Fossil Record ◽

Direct Evidence ◽

Directional Asymmetry ◽

Fundamental Aspect ◽

Lateral Asymmetry ◽

Morphological Asymmetry ◽

Fossil Evidence ◽

Behavioural Asymmetries ◽

Life On Earth ◽

Body Fossil

Asymmetry is a fundamental aspect of the biology of all organisms, and has a deep evolutionary history. The fossil record contains evidence of both morphological and behavioural asymmetries. Morphological asymmetry is most commonly expressed as conspicuous, directional asymmetry (either lateral asymmetry or spiral asymmetry) in body fossils. Few examples of fluctuating asymmetry, a form of subtle asymmetry, have been documented from fossils. Body fossil evidence indicates that morphological asymmetry dates to the time of the appearance of the first life on Earth (Archaean Eon). Behavioural asymmetry can be assumed to have been concomitant with conspicuous morphological asymmetry, but more direct evidence is in the form of trace fossils. Trace fossil evidence suggests that behavioural asymmetry, including nervous system lateralization, was in existence by the beginning of the Palaeozoic Era.

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A molecular palaeobiological exploration of arthropod terrestrialization

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2015.0133 ◽

2016 ◽

Vol 371 (1699) ◽

pp. 20150133 ◽

Cited By ~ 66

Author(s):

Jesus Lozano-Fernandez ◽

Robert Carton ◽

Alastair R. Tanner ◽

Mark N. Puttick ◽

Mark Blaxter ◽

...

Keyword(s):

Divergence Times ◽

Crown Group ◽

Terrestrial Arthropods ◽

Biological Adaptation ◽

Fossil Evidence ◽

History Of ◽

Terrestrial Fungi ◽

Terrestrial Biodiversity ◽

Body Fossil ◽

Colonization Of Land

Understanding animal terrestrialization, the process through which animals colonized the land, is crucial to clarify extant biodiversity and biological adaptation. Arthropoda (insects, spiders, centipedes and their allies) represent the largest majority of terrestrial biodiversity. Here we implemented a molecular palaeobiological approach, merging molecular and fossil evidence, to elucidate the deepest history of the terrestrial arthropods. We focused on the three independent, Palaeozoic arthropod terrestrialization events (those of Myriapoda, Hexapoda and Arachnida) and showed that a marine route to the colonization of land is the most likely scenario. Molecular clock analyses confirmed an origin for the three terrestrial lineages bracketed between the Cambrian and the Silurian. While molecular divergence times for Arachnida are consistent with the fossil record, Myriapoda are inferred to have colonized land earlier, substantially predating trace or body fossil evidence. An estimated origin of myriapods by the Early Cambrian precedes the appearance of embryophytes and perhaps even terrestrial fungi, raising the possibility that terrestrialization had independent origins in crown-group myriapod lineages, consistent with morphological arguments for convergence in tracheal systems. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’.

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Haootia quadriformis n. gen., n. sp., interpreted as a muscular cnidarian impression from the Late Ediacaran period (approx. 560 Ma)

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2014.1202 ◽

2014 ◽

Vol 281 (1793) ◽

pp. 20141202 ◽

Cited By ~ 46

Author(s):

Alexander G. Liu ◽

Jack J. Matthews ◽

Latha R. Menon ◽

Duncan McIlroy ◽

Martin D. Brasier

Keyword(s):

Muscle Tissue ◽

Indirect Evidence ◽

Muscle Fibres ◽

Muscular Tissue ◽

Early Cambrian ◽

Geological Record ◽

Fossil Evidence ◽

Body Fossil

Muscle tissue is a fundamentally eumetazoan attribute. The oldest evidence for fossilized muscular tissue before the Early Cambrian has hitherto remained moot, being reliant upon indirect evidence in the form of Late Ediacaran ichnofossils. We here report a candidate muscle-bearing organism, Haootia quadriformis n. gen., n. sp., from approximately 560 Ma strata in Newfoundland, Canada. This taxon exhibits sediment moulds of twisted, superimposed fibrous bundles arranged quadrilaterally, extending into four prominent bifurcating corner branches. Haootia is distinct from all previously published contemporaneous Ediacaran macrofossils in its symmetrically fibrous, rather than frondose, architecture. Its bundled fibres, morphology, and taphonomy compare well with the muscle fibres of fossil and extant Cnidaria, particularly the benthic Staurozoa. Haootia quadriformis thus potentially provides the earliest body fossil evidence for both metazoan musculature, and for Eumetazoa, in the geological record.

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Possible poriferan body fossils in early Neoproterozoic microbial reefs

Nature ◽

10.1038/s41586-021-03773-z ◽

2021 ◽

Author(s):

Elizabeth C. Turner

Keyword(s):

Molecular Phylogeny ◽

Physical Characteristics ◽

The Body ◽

Physical Evidence ◽

Microbial Carbonates ◽

Fossil Evidence ◽

Petrographic Feature ◽

Body Fossil ◽

Early Neoproterozoic ◽

Neoproterozoic Era

AbstractMolecular phylogeny indicates that metazoans (animals) emerged early in the Neoproterozoic era1, but physical evidence is lacking. The search for animal fossils from the Proterozoic eon is hampered by uncertainty about what physical characteristics to expect. Sponges are the most basic known animal type2,3; it is possible that body fossils of hitherto-undiscovered Proterozoic metazoans might resemble aspect(s) of Phanerozoic fossil sponges. Vermiform microstructure4,5, a complex petrographic feature in Phanerozoic reefal and microbial carbonates, is now known to be the body fossil of nonspicular keratosan demosponges6–10. This Article presents petrographically identical vermiform microstructure from approximately 890-million-year-old reefs. The millimetric-to-centimetric vermiform-microstructured organism lived only on, in and immediately beside reefs built by calcifying cyanobacteria (photosynthesizers), and occupied microniches in which these calcimicrobes could not live. If vermiform microstructure is in fact the fossilized tissue of keratose sponges, the material described here would represent the oldest body-fossil evidence of animals known to date, and would provide the first physical evidence that animals emerged before the Neoproterozoic oxygenation event and survived through the glacial episodes of the Cryogenian period.

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TRESISE, G. with SARJEANT, W.A.S. The tracks of Triassic vertebrates. Fossil evidence from northwest England. The Stationery Office, London: 1997, Pp xii, 204. Price £65. ISBN 0-11-290498-X.

Archives of Natural History ◽

10.3366/anh.1999.26.2.297a ◽

1999 ◽

Vol 26 (2) ◽

pp. 297-298

Author(s):

STEVE MCLEAN

Keyword(s):

Fossil Evidence

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Robert E. Grant's later views on organic development: the Swiney lectures on “Palaeozoology”, 1853–1857

Archives of Natural History ◽

10.3366/anh.1984.11.3.395 ◽

1984 ◽

Vol 11 (3) ◽

pp. 395-413 ◽

Cited By ~ 4

Author(s):

ADRIAN DESMOND

Keyword(s):

Steady State ◽

Development Theory ◽

Fossil Evidence

SUMMARY R. E. Grant's advocacy of transmutation is considered in relation to the scientific climate of the 1850s. To understand the palaeontological framework of his development theory, the unpublished “Palaeozoology” lectures, delivered in 1853–7, are analysed and his sources tabulated. The lectures are shown to contain the following additional themes: (1) a refutation of Lyell's steady-state geology, (2) support for serial development, (3) use of metamorphic effacement to explain the lack of pre-Silurian fossils, and (4) nebular hypothesis. The difficulty of supporting serial development using fossil evidence at this late date is discussed, and this difficulty is deemed to have contributed to the failure of Grant's theory of species “generation”.

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