Flora
The present site is occupied by a mixture of cultivated crops and some boreal trees such as fir, birch and thuya. But some 370 million years ago, the coast was a tropical estuary populated with abundant primitive life-forms, many of great evolutionary and phylogenetic interest. The macroflora includes 10 species of the first vascular plants of Devonian forests: algae and some 80 spore fossil species, Archaeopteris halliana, a 20m tall spore-bearing precursor to the modern Gymnosperma and Spermasposita which is considered the oldest flowering plant.
Fauna
(...) A two-million-year representation of Devonian life is preserved in the remarkably rich fossil beds exposed in the cliffs of Miguasha. There more than 100 vertebrate species notably fish, invertebrate species such as the 30cm Petaloscorpio bureaui, the first terrestrial scorpion, a fossil centipede discovered in 2003, ten species of primitive plants, algae and micro-organisms. These have allowed scientists to construct an almost complete picture of Devonian life of the time. In the warm tidal waters an astonishing variety of fish thrived, 21 species of which made Miguasha famous. Some were spiny, some armour-plated and the crossopterygian Eusthenopteron foordi had already developed the limb-like fins that enabled them to crawl across mud flats and the two-way gills and lung system, which gave rise to the modern conception of evolution from fish to four-limbed terrestrial tetrapod vertebrates.
None of some 60 Devonian period fossil sites worldwide matches Miguasha in abundance of specimens, representation of vertebrate evolution in the oldest known ancestral amphibian, and in quality of preservation: the fossils even of soft body parts, gill imprints, digestive traces, and the cartilaginous parts of skeletons remain in exceptional condition. Some 5,000 fossils have been identified, described, stored and computerised. Important specimens include Legendrelepis parenti of the jawless Agnatha fish group and unique to the Escuminac Formation; Diplocanthus horridus of the Acanthodian spiny fish group, and the first jawed fish to evolve; Bothriolepis canadensis of the then common bony-shielded Placoderms; Cheirolepis canadensis of the Actinopterygian group, from which 90% of all fish (over 29,000 taxa) derive; Miguashaia bureaui, morphologically identical to Latimeria chalumnae, the sole Coelacanthi of today; Scaumenacia curta, a fossil fish with both lungs and gills - an important climatic indicator, and Eusthenopteron foordi of the crossopterygian group. In addition, Petaloscorpio bureaui, is an important scorpionid indicator of the paleoenvironment. Of the eight fish groups associated with this period, six are found at Miguasha; the other two are typically marine. This representation is uncommon among sites of the same age and this is the only Devonian site on the World Heritage List.
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