Oxendean Burn

Site of Special Scientific Interest · 55.7973, -2.3654

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Also within

Berwickshire County

Condition (NatureScot)

Favourable (1)
UnitFeatureConditionArea (ha)Assessed
F1 Silurian - Devonian Chordata Favourable — 2009-05-05

Habitats

Fast flowing river and stream

Geology & landscape

Geological Period: Devonian · Rock Type: Mudstone, Sandstone

Description

Oxendean Burn Oxendean Burn Site of Special Scientific Interest (SSSI) lies approximately 4 km to the north of Duns and flows into the Whiteadder Water. The site comprises a 400 metre section of the Oxendean Burn where the river cuts through and exposes rocks originally formed from sediment carried by rivers flowing from mountains to the north and south during the Devonian Period of geological history, about 360 million years ago. These rocks are important geologically as they contain the fossilised remains of primitive fish that lived at this time. A lower fish bed consisting of mudstone is packed with fossilised fish remains and is thought to represent a pond, associated with an ancient river system, which dried out killing the fish. An upper fish bed about 6 metres above this, and consisting of sandstone, contains fish remains that have been transported and sorted by running streams. Oxendean Burn is of international importance as it is the only known locality for Bothriolepis hayi, an armoured fish with well-developed articulated jaws, making it the ‘type locality’ for the species. The study of these early fish is of importance because of the evidence it supplies concerning the evolution of the vertebrates, or backboned animals.

Plant communities

A14 — Fast flowing river and stream

Myriophyllum alterniflorum community

Isolepis fluitans, Juncus bulbosus, Fontinalis antipyretica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Lemna minor, Callitriche stagnalis, Littorella uniflora, Potamogeton filiformis, Potamogeton gramineus, Potamogeton natans, Ranunculus peltatus, Chara spp., Nitella hyalina

A17 — Chalk river and stream, Fast flowing river and stream

Ranunculus penicillatus ssp. pseudofluitans community

Berula erecta, Nasturtium officinale, Elodea canadensis, Lemna minor, Callitriche stagnalis, Veronica beccabunga, Polygonum amphibium, Polygonum hydropiper, Potamogeton crispus, Potamogeton pectinatus, Ranunculus penicillatus ssp. pseudofluitans

A18 — Fast flowing river and stream

Ranunculus fluitans community

Fontinalis antipyretica, Fontinalis squamosa var. curnowii, Myriophyllum alterniflorum, Myriophyllum spicatum, Elodea canadensis, Mentha aquatica, Lemna gibba, Lemna minor, Potamogeton perfoliatus, Ranunculus fluitans, Glyceria fluitans, Phalaris arundinacea

A9 — Fast flowing river and stream, Marginal and inundation, Pond ditch and canal, Sluggish river and stream

Potamogeton natans community

Schoenoplectus lacustris, Juncus bulbosus, Sparganium angustifolium, Sparganium erectum, Sparganium minimum, Alisma plantago-aquatica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Elodea canadensis, Lemna minor, Lemna trisulca, Nymphaea alba, Callitriche platycarpa, Callitriche stagnalis, Littorella uniflora, Potamogeton natans, Ranunculus trichophyllus, Glyceria fluitans, Chara subspinosa