Macrorhizodus
Macrorhizodus is an extinct genus of mackerel shark which lived from the early Eocene to early Oligocene epoch of the Paleogene period. It is often considered ancestral to Isurus and sometimes considered part of it. Macrorhizodus is also likely ancestral to Cosmopolitodus. It seems to be related to Isurolamna. It is known from isolated teeth and vertebral centra as well as at least two associated dentitions. It is an incredibly widespread shark, known from every continent except Australia. This includes a report from Antarctica.

Mason Hintermeister · CC BY-SA 4.0 · via Wikipedia/Commons. May be a photograph of a specimen, or an artist’s reconstruction — an interpretation of a skeleton, since colour and soft tissue are almost never preserved.
On record
Recorded, not inferred- Sits inside
- LamnidaePBDB
- Diet
- carnivorePBDB, for Lamniformes
- Life habit
- nektonicPBDB, for Lamniformes
- Motility
- actively mobilePBDB, for Lamniformes
Time the record covers
At least 14 million years on record.
The record covers at least 48.07 Mya to 33.9 Mya. No occurrence read is dated outside 56 Mya to 23.04 Mya.
75 occurrences of Macrorhizodus on record, most of them in the Eocene. Bar height is expected occurrences, not a count: each fossil is spread across the span it is dated to, so a tall narrow bar means tight dating and a low wide one means loose.
When
75 occurrencesThese are dates about fossils, not the animal: the record can only begin after it arose and end before it died out, so either end may reach further. Shares are expected occurrences: a fossil dated to a span is counted partly in each period it straddles. More on what this infers.
Found in
35 formations
- Gehannam Formation14
- Birket Qarun Formation7
- La Meseta Formation5
- Tallahatta Formation · Claiborne Group3
- Gosport Sand Formation · Claiborne Group3
- Lisbon Formation · Claiborne Group2
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The named rock units Macrorhizodus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 11 further formations hold fewer occurrences each and are not listed. 5 occurrences have no formation on record, which is common for older literature.
Macrorhizodus and its relatives
EoceneWhere Macrorhizodus and its relatives were recorded in the Eocene.
Found in the same rock
511 taxa- Striatolamia macrota31 sites
- Myliobatis21 sites
- Rhinoptera14 sites
- Abdounia12 sites
- Otodus auriculatus12 sites
- Physogaleus secundus12 sites
- Brachycarcharias lerichei11 sites
- Brachycarcharias twiggsensis11 sites
- Physogaleus11 sites
- Hypotodus verticalis10 sites
- Odontaspis winkleri10 sites
- Sphyraena10 sites
- Abdounia minutissima9 sites
- Galeorhinus9 sites
- Jaekelotodus robustus9 sites
- Negaprion gilmorei9 sites
- Odontaspididae9 sites
- Otodus (Carcharocles) sokolowi9 sites
- Propristis schweinfurthi9 sites
- Aetomylaeus8 sites
- Carcharias8 sites
- Hemipristis curvatus8 sites
- Paralopias alabamensis8 sites
- Pristis8 sites
The Paleobiology Database records 49 sites for Macrorhizodus, and this reads all of them. The number is how many of those sites it was catalogued from too. The 24 sharing the most are listed.
This is not a list of everything alive at the time. It is only what has come out of the same ground as this animal and been written down.
Entered from
27 references- Shark and ray faunas in the Middle and Late Eocene of the Fayum Area, Egypt21
- Taxonomy and biostratigraphy of the elasmobranchs and bony fishes (Chondrichthyes and Osteichthyes) of the lower-to-middle Eocene (Ypresian to Bartonian) Claiborne Group in Alabama, USA, including an analysis of otoliths7
- Middle Eocene chondrichthyan fauna from Antarctic Peninsula housed in the Museo de La Plata, Argentina5
- The Turanian Basin in the Eocene: the new data on the fossil sharks and rays from the Kyzylkum Desert (Uzbekistan)5
- Elasmobranchii and Palaeogene biostratigraphy of Trans Urals and central Asia5
- Sharks and rays from the Mokattamian Stage (middle and late Eocene) of Egypt, including some species from the middle Eocene Midra Shale of Qatar4
- Records of elasmobranchian teeth in the Bartonian of the northern Caucasus (Russia) and Crimea (Ukraine)3
- Neoselachians and Chimaeriformes (Chondrichthyes) from the latest Cretaceous-Paleogene of Sierra Baguales, southernmost Chile. Chronostratigraphic, paleobiogeographic and paleoenvironmental implications3
- Late Eocene fishes from the Tupelo Bay Formation of South Carolina, USA2
- Chondrichthyan fishes from the Middle Eocene Osinovaya Formation of Rostov Region, Russia2
- A Middle–Late Eocene vertebrate fauna (marine fish and mammals) from southwestern Morocco; preliminary report: age and palaeobiogeographical implications2
- Preliminary report on the fishes (Chondrichthyes & Teleostei) from the lower Oligocene (Rupelian) Red Bluff Clay at site AMo-9, Monroe County, Alabama, USA1
Each of the 75 occurrences read was entered from one of these publications, ordered by how many each accounts for. This is not a search for papers mentioning the name. 15 further references are not listed. Entries link to doi.org where the Paleobiology Database holds an identifier, and to its own record where it does not. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.
Media and terms
Media content1
Picture of Macrorhizodus
- Source
- Wikipedia/Commons
- Credit
- Mason Hintermeister
- Licence
- CC BY-SA 4.0
- Commercial use
- the licence allows it
No 3D scan of Macrorhizodus was found in Sketchfab.
Smithsonian Open Access and MorphoSource were not reached for this taxon, so this list is what the others held rather than everything there is.
The description on this site
- Licence
- CC BY-SA 4.0
This is what the site found, which is not the same as what exists.
Keep going
What may have been alongside itLamnidae through timeFormations of the EoceneThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Glikman 1964