Nannometioceras Ammonite Fossil Upper Cenomanian Cretaceous Texas USA Genuine COA

Description

Rare Nannometioceras Ammonite Fossil from Texas, USA

This is a genuine Nannometioceras ammonite fossil from the Upper Cenomanian stage of the Late Cretaceous, discovered at Britton Farm, North Dallas, Texas, USA. This beautifully preserved fossil dates back approximately 95–93 million years, a period when ammonites thrived in the warm shallow seas that once covered much of North America. The specimen offered here is the exact fossil shown in the photos, complete with a 1 cm scale cube for size reference. As with all our fossils, it comes with a Certificate of Authenticity, guaranteeing that you are purchasing a genuine specimen.

Geological Age and Provenance

The Cenomanian stage marks the first subdivision of the Late Cretaceous and is renowned for its rich marine deposits. During this time, much of Texas was submerged beneath the Western Interior Seaway, a vast inland sea that stretched from the Gulf of Mexico to the Arctic. The Britton Formation, where this ammonite was found, is particularly well-known for its fossiliferous layers, which preserve an extraordinary record of life from this age.

Fossils from this formation help paleontologists reconstruct the complex marine ecosystems of the Late Cretaceous. Ammonites such as Nannometioceras serve as valuable index fossils, allowing geologists to correlate rock layers across wide regions due to their distinctive morphology and rapid evolutionary changes.

Scientific Classification

• Fossil Type: Ammonite
• Genus: Nannometioceras
• Order: Ammonitida
• Superfamily: Acanthoceratoidea
• Geological Stage: Upper Cenomanian, Late Cretaceous (~95–93 million years ago)
• Locality: Britton Farm, North Dallas, Texas, USA

Morphological Features

The genus Nannometioceras is noted for its compact, tightly coiled shells with prominent ribbing that extends across the whorls. Distinctive features often observed in this genus include:

• Ornamented ribbing that accentuates the whorl profile.
• A compressed, planispiral shell structure, typical of ammonites.
• Strongly defined suture patterns, which provide critical identification traits.
• A relatively small to medium size, making it distinct from larger Cenomanian ammonites.

These features not only enhance its aesthetic appeal but also aid scientific classification, helping to distinguish Nannometioceras from other closely related genera of the Cenomanian seas.

Paleoenvironment and Ecology

During the Cenomanian, the seas of Texas were rich in marine life, from ammonites and belemnites to fish, marine reptiles, and invertebrates. Nannometioceras ammonites were nektonic carnivores, capable of swimming actively through the water column. They likely fed on smaller invertebrates, using their tentacles to capture prey.

The preservation of this fossil reflects the fine-grained marine sediments that quickly buried ammonite shells after death. These deposits not only protected the shells from erosion but also ensured that intricate morphological details, such as ribbing and suture lines, remain visible millions of years later.

Collector and Scientific Significance

This Nannometioceras ammonite fossil is an exceptional piece for collectors, both for its rarity and for its provenance from a classic American fossil site. Its well-preserved form captures the elegance of ammonite morphology while offering insight into the diverse ecosystems of the Western Interior Seaway.

For paleontologists, fossils such as this serve as important data points for biostratigraphy and paleoenvironmental reconstruction. For collectors and enthusiasts, it represents an outstanding display piece and a tangible connection to Earth’s distant Cretaceous seas.

Key Details

• Species: Nannometioceras ammonite
• Age: Upper Cenomanian, Late Cretaceous (~95–93 million years old)
• Location: Britton Farm, North Dallas, Texas, USA
• Features: Ribbed shell, planispiral coiling, distinct suture patterns
• Authenticity: 100% genuine fossil with Certificate of Authenticity
• Exact Specimen: You will receive the fossil shown in the photos
• Scale Reference: 1 cm cube included for accurate size

This rare Nannometioceras ammonite fossil from Texas is a scientifically valuable and visually striking specimen, ideal for collectors of fine ammonites, students of paleontology, or anyone with an appreciation for natural history treasures.