(1) These data support the concept that variable and J region sequence have been conserved in the evolution of placoderm-derived vertebrates, but that constant regions show much greater phylogenetic variation.
(2) Of over 60 agnathan and fish genera known, only 5 placoderms (Givetian-Famennian) are cosmopolitan.
(3) The only detectable DNP-binding protein in the serum of placoderm-derived vertebrates was immunoglobulin in nature, and of the order of less than or equal to 1% total serum immunoglobulin.
(4) Molecular genetic studies of placoderm derived vertebrates are incomplete but are sufficient to allow the conclusion that Igs of these species are specified by variable (V), joining (J) and constant (C) gene segments and that rearrangement are an essential feature for the generation of antibody diversity.
Silurian
Definition:
(a.) Of or pertaining to the country of the ancient Silures; -- a term applied to the earliest of the Paleozoic eras, and also to the strata of the era, because most plainly developed in that country.
(n.) The Silurian age.
Example Sentences:
(1) – Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous … 'What will survive of us is love', wrote Philip Larkin.
(2) Recent work on Silurian, Devonian and Carboniferous terrestrial assemblages has provided plausible evidence for all major groups of extant fungi in the Paleozoic.
(3) Silurian vertebrates occur in southern, eastern and western parts of the country and are familiar from horizons as low as Llandovery.
(4) Hitching library had a copy and the library service sent a request stating that there was a boy in Chorleywood eager to know more about Silurians and Seeds of Doom.
(5) The spatial arrangement of the vertical canals is already present in fossil ostracoderms, and is also exemplified in lampreys, the modern forms of once abundant agnathan species that populated the Silurian and Devonian oceans.
(6) A review of the vertebrates within the Silurian and Devonian of China suggests a more detailed picture of palaeobiogeographical distribution than previously possible.