biology

Otodus angustidens

Otodus angustidens is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Otodus angustidens rather than just read about it. In short: Otodus angustidens is an extinct species of prehistoric megatoothed sharks in the genus Otodus, which lived during the Late Eocene and Miocene epochs about 34 to 21 million years ago. The largest individuals were about 11–12 metres (36–39 ft) long.

Key takeaways

Otodus angustidens belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Otodus angustidens to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Otodus angustidens from memory before moving on to harder problems.

Reference excerpt

Otodus angustidens is an extinct species of prehistoric megatoothed sharks in the genus Otodus, which lived during the Late Eocene and Miocene epochs about 34 to 21 million years ago. The largest individuals were about 11–12 metres (36–39 ft) long. This shark is related to another extinct megatoothed shark, the famous Otodus megalodon.

Taxonomy The Swiss naturalist Louis Agassiz, first identified this shark as a species of genus Carcharodon in 1843. In 1964, shark expert, L. S. Glikman recognized the transition of Otodus obliquus to O. auriculatus and moved O. angustidens to genus Otodus. (See "external links" below) However, in 1987, shark expert H. Cappetta recognized the O. auriculatus - O. megalodon lineage and placed all related megatooth sharks along with this species in the genus Carcharocles. The complete Otodus obliquus to O. megalodon transition then became clear and has since gained the acceptance of many other experts with the passage of time. Within the Otodus lineage, O. angustidens is the species succeeding O. sokolovi and is followed by O. chubutensis.The transition between O. angustidens and O. chubutensis, which began in the late Oligocene, is estimated to have taken a considerable amount of time.

In 2001, a discovery of the best preserved Otodus angustidens specimen to date by two scientists, Michael D. Gottfried and Ewan Fordyce, has been presented by the team as evidence for close morphological ties with the extant great white shark, and the team argued that Otodus angustidens, along with all other related megatooth sharks, including Otodus megalodon, should be assigned to Carcharodon as was done before by Louis Agassiz., although this is not internationally accepted by the scientific community. A more recent study of the taxonomic relationships of the related Megalolamna demonstrates the possibility that Otodus needs to include the species sometimes assigned to Carcharocles (i.e., the megatoothed lineage, including megalodon) in order to be monophyletic.

Size estimation Like other known megatooth sharks, the fossils of O. angustidens indicate that it was considerably larger than the extant great white shark, with the largest individuals possibly measuring up to 11–12 metres (36–39 ft) long. A well preserved specimen from New Zealand is estimated at 9.3 m (31 ft) in length. This specimen had teeth measuring up to 9.87 cm (3.89 in) in diagonal length, and vertebral centra around 1.10 cm (0.43 in) in diameter. Smaller individuals were about 6–6.6 metres (20–22 ft) long, still larger than the average extant great white shark.

Dentition The dental formula for O. angustidens is 2.1.5.43.0.6.3

Diet O. angustidens was an apex predator and likely preyed upon penguins, fish, dolphins, and baleen whales.

Fossil record As is the case with most extinct sharks, this species is also known from fossil teeth and some fossilized vertebral centra. Shark skeletons are composed of cartilage and not bone, and cartilage rarely gets fossilized. Hence, fossils of O. angustidens are generally poorly preserved. To date, the best preserved specimen of this species have been excavated from New Zealand, which comprises 165 associated teeth and about 35 associated vertebral centra. This specimen is around 26 million years old. O. angustidens teeth are noted for their triangular crowns and small side cusps that are fully serrated. The serrations are very sharp and very well pronounced. O. angustidens was a widely distributed species with fossils found in: A fossil bed in South Carolina suggests that O. angustidens utilized the area as a birthing ground and nursery for their pups, as 89% of the teeth found in the area belonged to juveniles, 3% belonged to infants, and 8% belonged to adults.Entering the early Miocene, there are many instances where the fossils of O. chubutensis and Megalodon overlap in age.

North America Yazoo Formation, Alabama Jewett Sand Formation, California Clinchfield Formation, Georgia Calvert Formation, Maryland Jackson Group, Mississippi Kirkwood Formation, New Jersey Castle Hayne Formation, North Carolina Hawthorne Formation, South Carolina Chandler Bridge Formation, South Carolina Europe Malta Paris Basin, France Leipzig / Stoermthal, Germany Asia Ashiya Group, Japan Bhuban Formation, India Oceania Ettric, Jan Juc, Gambier Limestone, Clifton Formations, Australia Otekaike Formation, New Zealand Africa South America Dos Bocas Formation, Ecuador

Illustrations

Worked examples

Example 1 — a first encounter with Otodus angustidens

Start with the simplest possible case. Write down what Otodus angustidens claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Otodus angustidens before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Otodus angustidens ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Otodus angustidens

In research: Otodus angustidens appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Otodus angustidens in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Otodus angustidens is common in secondary-school and first-year university syllabi. It links to neighbouring topics Aquitanian species extinctions, Chattian species first appearances, Fossil taxa described in 1843, so understanding it makes those chapters shorter.
In everyday life: Look for Otodus angustidens outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Otodus angustidens in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Otodus angustidens means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Otodus angustidens out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Otodus angustidens in simple terms?

Why does Otodus angustidens matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Otodus angustidens?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Otodus angustidens.