# Tangahoe Formation

The Tangahoe Formation is a geologic formation in the southwestern North Island of New Zealand.
The formation occurs in the Taranaki and Manawatu-Wanganui Regions, spreading in an east–west band for 200 kilometres (120 mi) from the volcanic deposits of Mount Taranaki in the west to the Ruahine Ranges in the east, in a band with an average width of around 20 kilometres (12 mi). It becomes exposed at its western end close to the Tasman Sea coast near Hāwera in a series of cliff faces. The formation takes its name from the Tangahoe River, close to the exposed cliffs.
The formation is sedimentary, composed largely of muddy sandstones, and was formed beneath sea level in the Waipipian stage of the mid-Pliocene some 3.4 to 3.0 million years ago.

## Fossil content

| 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. |
The formation is an important fossil site. Many marine fossils have been recovered from its mudstones, including the megalodon shark, giant petrel Macronectes tinae, penguin Eudyptes atatu, monk seal Eomonachus belegaerensis, and cetaceans.

### Mammals

Mammals reported from the Tangahoe Formation :
| Genus | Species | Presence | Material | Notes | Images |
| Delphinidae indet. | Indeterminate | Waihi Beach | Mandible. | A dolphin, probably from a species of Delphinus or Stenella. | |
| Eomonachus | E. belegaerensis | Northwest of Waihi Stream on Ohawe and Waihi Beaches. | Skull elements. | A monk seal. | |

### Birds

Birds reported from the Tangahoe Formation :
| Genus | Species | Presence | Material | Notes |
| Aldiomedes | A. angustirostris | Ohawe Beach. | Skull. | An albatross. |
| Ardenna | A. buchananbrowni | Ohawe & Waihi beaches. | 2 partial skeletons. | A shearwater. |
| Ardenna | A. davealleni | Ohawe Beach. | Partial skeleton. | A shearwater. |
| Eudyptes | E. atatu | No exact locality record. | Multiple partial skeletons. | A penguin. |
| Eudyptula | E. wilsonae | No exact locality record. | Skulls. | A penguin. |
| Macronectes | M. tinae | Hawera. | Skull & humerus. | A petrel. |
| Pelagornithidae | Undescribed | Waihi Beach. | Partial humerus & radius. | An unnamed species of pseudotooth bird. |
| Procellaria | P. altirostris | Ohawe Beach. | Partial skeleton. | A petrel. |
| Tereingaornis | T. moisleyi | Waihi Beach. | Left humerus & coracoid. | A penguin, now deemed a nomen dubium. |

### Fish

Fish reported from the Tangahoe Formation :
| Genus | Species | Presence | Material | Notes |
| Carcharodon | C. megalodon | Hawera. | Vertebrae. | Species now moved to Otodus. |
| Ikamauius | I. ensifer | Waihi Beach. | Rostral denticle. | A sawshark. |
| Otodus | O. megalodon | Hawera. | Vertebrae. | A megatooth shark, originally reported as Carcharodon megalodon. |
| Pristiophorus | P. lanceolatus | Northwest of the Tangahoe River mouth. | Rostral denticle. | Species now deemed a nomen dubium, specimen reassigned as P. sp. |
| Pristiophorus | P. sp. | Northwest of the Tangahoe River mouth. | Rostral denticle. | A sawshark, originally reported as P. lanceolatus. |
| cf. Tetrosomus | cf. T. sp. | Waihi Beach | A near-complete articulated specimen. | A boxfish. |

### Invertebrates

Invertebrates reported from the Tangahoe Formation :
| Genus | Species | Presence | Material | Notes | Images |
| Palaega | P. kakatahi | Between Raukawa Falls & Kakatahi. | A single specimen. | A cirolanid isopod. | |