# Gun River Formation

The Gun River Formation is a geologic formation in Quebec. It preserves fossils dating back to the early Silurian period.

## Description

The formation is divided into 4 members (from the base up): the Lachute, Innommée, Sandtop and Macgilvray members. The formation was deposited some 40–80 km offshore from the stable Laurentian craton, underwater at depths of 30 to 60 meters.

## Fossil content
### Vertebrates

| Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon | Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited. |
Conodonts :
| Genus | Species | Presence | Notes |
| Anticostiodus | A. fahraeusi | Anticosti Island. | |
| Anticostiodus | A. boltoni | Anticosti Island. | |
| Icriodella | I. deflecta | | Probably instead belongs to the Jupiter Formation. |

### Invertebrates

Brachiopods :
| Genus | Species | Presence | Material | Notes |
| Brachyprion | | Sandtop and Macgilvray Members. | | A strophomenid. |
| Coolinia | | Sandtop and Macgilvray Members. | | |
| Fenestrirostra | F. glacialis | Lowermost part of the formation. | | A rhynchonellidalso found in the Merrimack Formation. |
| Fenestrirostra | F. pyrrha | Lachute Member. | | A rhynchonellid. |
| 'Gotatrypa' | 'G.' sp. | Innommée Member. | | |
| Hyattidina | | Sandtop to Macgilvray Members. | | An athyrid. |
| Joviatrypa | | Uppermost Macgilvray Member. | | |
| Kulumbella | K. xacta | Upper Macgilvray Member. | | A pentamerid. |
| Mendacella | | Innommée Member. | | A dalmanellid. |
| Meristina | | Innommée Member. | | |
| Pentamerus | P. palaformis | Top of the formation (uppermost Macgilvray Member). | | Also found in the Jupiter Formation. |
| Stegerhynchus | | | | |
| Stricklandia | S. gwelani | Top of the formation (Macgilvray Member). | | Also found in the Jupiter Formation. |
| Stricklandia | S. sp. | Innommée Member. | A509 (7 broken valves on a slab). | Also found in the uppermost Merrimack Formation. |
| Sypharatrypa | S. sp. | Innommée Member. | | |
Bryozoans :
| Genus | Species | Material | Notes |
| Phaenopora | P. superba | | Also found in the Becscie Formation. |
| Ptilodictya | P. canadensis | USNM 143039. | |
| Ptilodictya | P. sulcata | USNM 143039, 143050; YPM 3063/98, 3063/104. | |
Corals :
| Genus | Species | Presence | Material | Notes |
| Acidolites | A. arctatus | | | A heliolitid. |
| Brachyelasma | | | | |
| Crassilasma | | | | |
| Helicelasma | | | | |
| Palaearaea | | Cap aux Goélands (Uppermost Macgilvray Member). | Small colonies. | The only rugosan coral known from the formation, also found in the Menier formation. |
| Paleofavosites | P. capax | | Multiple colonies. | A tabulate coral. |
Crinoids :
| Genus | Presence |
| Dendrocrinus | |
| Eumyelodactylus | Macgilvray Member. |
| Laurocrinus | Macgilvray Member. |
| Stupatocrinus | Macgilvray Member. |
Graptolites :
| Genus | Species | Presence | Material | Notes | Images |
| Paraclimacograptus | P. cf. innuitus | Deeper water facies of the Sandtop Member. | | | |
Sponges :
| Genus | Species | Presence | Material | Notes | Images |
| Camptodictyon | | | | A stromatoporoid. | |
| Clathrodictyon | | | | A stromatoporoid. | |