Following the Ordovician extinction event there was a rapid recovery of invertebrate faunas during the Silurian. The high sea levels and warm shallow continental seas provided a hospitable environment for marine life of all kinds. The biota and ecological dynamics were basically still similar to that of the Ordovician, but was more diverse
Brachiopods are the most common hard-shelled organisms, making up 80% of the total species. Among these, pentamerids first appear and are abundant, rhynchonellids, and the spire-bearing athyridids and atrypidids are also common, as are other groups that continue from the Ordovician.
Tropical reefs are common in the shallow seas of this period, formed by tabulate and rugose corals, stromatoporoid organisms, bryozoa and calcareous algae. Trilobites, cephalopods, gastropods, and echinoderms. The Trilobites, having reached their acme in the Cambrian and Ordovician, are now in decline. The trinucleids and asaphids are absent, whilst encrinites and illaenids do not survive the end of the Silurian
Planktonic graptolites remain common and diverse. The single-spined Monograptus is the predominant genus, and its species are useful as zone fossils.
Jawless fish invade brackish and fresh water, as do eurypterids, xiphosurids, scorpions, which may have been semi-aquatic. rhyniophytes, primitive lycophytes, and myriapods became the first proper land organisms. At the end of the period Jawed fish appeared for the first time, but they remain insignificant.
Brachiopods are the most common hard-shelled organisms, making up 80% of the total species. Among these, pentamerids first appear and are abundant, rhynchonellids, and the spire-bearing athyridids and atrypidids are also common, as are other groups that continue from the Ordovician.
Tropical reefs are common in the shallow seas of this period, formed by tabulate and rugose corals, stromatoporoid organisms, bryozoa and calcareous algae. Trilobites, cephalopods, gastropods, and echinoderms. The Trilobites, having reached their acme in the Cambrian and Ordovician, are now in decline. The trinucleids and asaphids are absent, whilst encrinites and illaenids do not survive the end of the Silurian
Planktonic graptolites remain common and diverse. The single-spined Monograptus is the predominant genus, and its species are useful as zone fossils.
Jawless fish invade brackish and fresh water, as do eurypterids, xiphosurids, scorpions, which may have been semi-aquatic. rhyniophytes, primitive lycophytes, and myriapods became the first proper land organisms. At the end of the period Jawed fish appeared for the first time, but they remain insignificant.
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