Ordovician faunas of Burgess Shale type
The discovery of numerous diverse soft-bodied assemblages in the Lower and Upper Fezouata Formations (Lower Ordovician) of Morocco are reported, which include a range of remarkable stem-group morphologies normally considered characteristic of the Cambrian.
Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps
Evidence shows that anomalocaridids represent a stage before the fusion of exite and endopod into the ‘Cambrian biramous limb’, confirming their basal placement in the euarthropod stem, rather than in the arthropod crown or with cycloneuralian worms.
A giant Ordovician anomalocaridid
Phylogenetic analyses support a position of anomalocaridids in the arthropod stem, as a sister group to the euarthropods, and confirm the presence of a dorsal array of flexible blades attached to a transverse rachis on the trunk segments.
A holomorph approach to xiphosuran evolution—a case study on the ontogeny of Euproops
A holomorph approach is proposed, i.e., reconstructing ontogenetic sequences for fossil and extant species as a sound basis for a taxonomic, phylogenetic, and evolutionary discussion of Xiphosura.
Ancestral morphology of crown-group molluscs revealed by a new Ordovician stem aculiferan
- J. Vinther, L. Parry, D. Briggs, P. Roy
- Geography, BiologyNature
- 23 February 2017
A new early sachitid is described from the Fezouata biota of Morocco, which strongly suggests that the possession of only a single calcareous shell plate and the presence of unmineralised sclerites are plesiomorphic for the molluscan crown.
An aglaspidid arthropod from the Upper Ordovician of Morocco with remarks on the affinities and limitations of Aglaspidida
- P. Roy
- Environmental ScienceTransactions of the Royal Society of Edinburgh…
- 1 December 2005
A new aglaspidid arthropod is described from the Pusgillian (lower Ashgill, Upper Ordovician) Upper Tiouririne Formation near Erfoud, southeastern Morocco and it is suggested that ag laspidids are probably more closely related to trilobites than they are to chelicerates.
Machaeridians are Palaeozoic armoured annelids
- J. Vinther, P. Roy, D. Briggs
- Geography, Environmental ScienceNature
- 10 January 2008
A new machaeridian with preserved soft parts, including parapodia and chaetae, from the Upper Tremadoc of Morocco, demonstrating the annelid affinity of the group is described, showing that a lineage of annelids evolved a dorsal skeleton of calcareous plates early in their history.
Anthropometric fractionation of body mass: Matiegka revisited
- E. Cattrysse, E. Zinzen, D. Caboor, W. Duquet, P. Roy, J. Clarys
- MedicineJurnal sport science
- 1 September 2001
In a group of 699 Belgian nursing professionals, we estimated body composition using the four-component anthropometric model, relying on the equations originally formulated by Matiegka in 1921 and…
A spinose appendage fragment of a problematic arthropod from the Early Ordovician of Morocco
- P. Roy, O. E. Tetlie
- Biology
- 2006
A highly spinose fragment of a possibly raptorial appendage from the Arenig (Early Ordovician) of the Upper Fezouata Formation north of Zagora, southeastern Morocco is described as the arthropod…
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