---
title: "What the sources say about the Duck-Billed Platypus | AnimalTracks.wiki"
description: "58 claims from the Duck-Billed Platypus profile, each beside the words of the source that backs it."
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# What the sources say about the Duck-Billed Platypus (*Ornithorhynchus anatinus*)

> 58 claims from the Duck-Billed Platypus profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Duck-Billed Platypus](https://animaltracks.wiki/animals/platypus/)

## Ornithorhynchus anatinus (duck-billed platypus). Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Ornithorhynchus_anatinus/

| The page says | The source says |
| :--- | :--- |
| High | They can harm humans with their venomous spurs if provoked (note: danger tier High = 'Dangerous when cornered or provoked' (facetMetadata.ts)) |
| Freshwater rivers, streams, and lagoons across eastern Australia and Tasmania | The geographic range of Ornithorhynchus anatinus is restricted to the wetter regions of eastern Australia and Tasmania ... Duck-billed platypuses inhabit rivers, lagoons, and streams |
| The species lives in the wetter regions of eastern Australia and Tasmania, in rivers, lagoons and streams | The geographic range of Ornithorhynchus anatinus is restricted to the wetter regions of eastern Australia and Tasmania ... Duck-billed platypuses inhabit rivers, lagoons, and streams |
| weightKg: 1.52 | Average mass
1.52 kg (note: task #708; ADW average adult mass. Light class (0.1 to 10 kg). In the curated matchup platypus vs lowland-streaked-tenrec.) |

## Platypus. San Diego Zoo Wildlife Alliance.

https://animals.sandiegozoo.org/animals/platypus

| The page says | The source says |
| :--- | :--- |
| Insect larvae, freshwater shrimp, crayfish, and worms caught on underwater dives | These underwater forays enable platypuses to feed on insect larvae, freshwater shrimp, freshwater crayfish called "yabbies" |
| Platypuses and echidnas are the only living mammals that lay eggs, and together they are called monotremes | Platypuses and echidnas are the only living mammals that lay eggs. They are called monotremes. |
| Males run 40 to 63 centimetres from bill to tail-tip and weigh up to 3 kilograms | Length from tip of bill to tip of tail: males 16 to 25 inches (40 to 63 centimeters) ... Weight: males: 1.8 to 6.6 pounds (0.8 to 3 kilograms) |
| females are smaller, at 37 to 55 centimetres and up to 1.7 kilograms | females 15 to 22 inches (37 to 55 centimeters) ... females: 1.3 to 3.7 pounds (0.6 to 1.7 kilograms) |
| Platypuses typically live 12 to 15 years | Life span: 12 to 15 years on average |
| By day it rests in a burrow dug along the bank, or under rock ledges, roots and debris | Male and female platypuses dig simple burrows along rivers and streams outside the breeding season. They can also make their home under rock ledges, roots, and debris, where they rest throughout the day. |
| It is not fatal to people | (It is not fatal to people, but is excruciating, and causes swelling.) |
| A spur can deliver enough venom to kill a medium-sized dog | If the spur pierces skin, it can release enough venom to kill a medium-sized dog. |
| There's more venom in the breeding season, which leads scientists to think males use it against rival males | The venom is more plentiful during breeding season, leading scientists to believe that it's used to defend mates and resources from rival males. |
| The bill carries 40,000 electroreceptors, which detect the electrical impulses living creatures make | about 40,000 electroreceptors help them find the direction and distance of prey (its eyes and ears are closed while it’s underwater) by detecting electrical impulses generated by living creatures (note: 40,000 also in manger-pettigrew-2008: 'There are 40,000 mucous gland electroreceptors found in the bill skin of the platypus') |
| Dives usually last 30 to 60 seconds or so and go less than 5 metres down | they may make repeated, short dives of 30 to 60 seconds or so ... they usually dive less than 16 feet (5 meters) |
| Prey goes into cheek pouches to be eaten at the surface: freshwater shrimp, crayfish called yabbies, worms and insect larvae | These underwater forays enable platypuses to feed on insect larvae, freshwater shrimp, freshwater crayfish called "yabbies" (which it nuzzles out of the riverbed with its snout or catches while swimming), and worms. They use cheek pouches to stow bounty until reaching the surface, where they can eat. |
| Hatchlings have molar-like milk teeth, but they're shed around the time the young leave the nesting burrow; adults grind food between pads made of keratin | don’t have teeth, but instead grind their food between mouth pads made of keratin ... freshly hatched platypuses have molar-like “milk teeth," but these are shed around the time they leave the nesting burrow |
| Only adult males have venom, which they deliver with spurs on their hind legs rather than by biting | Adult male platypuses have venomous spurs, an unusual characteristic among mammals (note: 'only males' per ADW 'Males are generally larger than females, and have two venom glands attached to spurs on their hind legs'; not-a-bite from defensins-2008 'Rather than delivering venom through a bite, as do snakes and shrews, male platypuses have venomous spurs on each hind leg') |
| A stomach, yes; teeth, only as babies | don’t have teeth, but instead grind their food between mouth pads made of keratin ... freshly hatched platypuses have molar-like “milk teeth," |
| Baby platypuses start with molar-like teeth and lose them around when they first leave the burrow | freshly hatched platypuses have molar-like “milk teeth," but these are shed around the time they leave the nesting burrow |
| From then on, pads made of keratin do the grinding | grind their food between mouth pads made of keratin |
| An egg-laying mammal | Platypuses and echidnas are the only living mammals that lay eggs. They are called monotremes. (note: tagline (final pass)) |
| tags: insectivore | These underwater forays enable platypuses to feed on insect larvae (note: task #708; the tag's definition is 'Hunting insects, spiders, and grubs'; aquatic insect larvae are grubs. The tag feeds no battle stat.) |
| hunts underwater with its eyes and ears shut | its eyes and ears are closed while it (note: vibe.reason, task #708) |
| steering by about 40,000 electroreceptors in its bill that pick up the electrical impulses of living prey | about 40,000 electroreceptors help them find the direction and distance of prey (note: vibe.reason; SDZ continues 'by detecting electrical impulses generated by living creatures'; in the bill per manger-pettigrew-2008 '40,000 mucous gland electroreceptors found in the bill skin') |

## Fenner, Williamson & Myers (1992). Platypus envenomation - a painful learning experience. Medical Journal of Australia.

https://doi.org/10.5694/j.1326-5377.1992.tb141302.x

| The page says | The source says |
| :--- | :--- |
| Intravenous narcotics could not control the pain from two spur wounds to one man's hand | A 57-year-old man was envenomated via two spur wounds to the right hand from each hind leg of a male platypus ... On admission to hospital, narcotics administered intravenously, both intermittently and by infusion, provided inadequate analgesia. |
| A nerve block at the wrist was dramatically effective | A right wrist block was dramatically effective. |
| That's from the first detailed medical report of a platypus envenomation, published in 1992, about a 57-year-old man spurred by a male platypus | To describe in detail for the first time, the clinical course and medical management of a significant human envenomation by the Australian platypus ... A 57-year-old man was envenomated via two spur wounds (note: 1992 is the paper's publication year (reference year)) |
| the venom produces "savage local pain and marked local swelling," and his hand did not work properly for three months | Significant functional impairment of the hand persisted for three months, the cause of which is uncertain. Conclusions Male platypus venom remains largely unstudied. It produces savage local pain and marked local swelling, but no apparent tissue ischaemia. |
| Yes, and painfully | Pain was immediate, sustained, and devastating |
| No antivenom exists | No antivenom is available |
| The 1992 report that first described a human case in detail concluded that blocking the nerves to the wounded area appears to be the only pain relief that works, and its patient spent six days in hospital | To describe in detail for the first time, the clinical course and medical management of a significant human envenomation ... The patient spent six days in hospital ... in its absence the only effective analgesia appears to be regional nerve blockade, when the envenomation site and available skills permit. (note: 1992 is the reference year) |

## Whittington et al. (2008). Defensins and the convergent evolution of platypus and reptile venom genes. Genome Research.

https://doi.org/10.1101/gr.7149808

| The page says | The source says |
| :--- | :--- |
| A genetics paper on the platypus's venom opens by noting that when the species was first found, it "was thought to be a taxidermist's hoax, as it has a blend of mammalian and reptilian features." | When the platypus (Ornithorhynchus anatinus) was first discovered, it was thought to be a taxidermist's hoax, as it has a blend of mammalian and reptilian features. |
| Male platypuses deliver venom through spurs on their hind legs, not through a bite | Rather than delivering venom through a bite, as do snakes and shrews, male platypuses have venomous spurs on each hind leg. |
| Its major components come from a repurposed antimicrobial gene: three venom genes arose when copies of a gene family called beta-defensins duplicated and changed function | While searching the platypus genome for the sequences of antimicrobial defensin genes, we identified three Ornithorhynchus venom defensin-like peptide (OvDLP) genes, which produce the major components of platypus venom. We show that gene duplication and subsequent functional diversification of beta-defensins gave rise to these platypus OvDLPs. |
| Some snakes and lizards make similar venom molecules, but theirs evolved separately, so the trick has evolved more than once | some species of snakes and lizards also produce venoms containing similar molecules called crotamines and crotamine-like peptides ... Here we show that several venom components have evolved separately in the platypus and reptiles. Convergent evolution has repeatedly selected genes coding for proteins containing specific structural motifs as templates for venom molecules. |
| with venomous spurs | Rather than delivering venom through a bite, as do snakes and shrews, male platypuses have venomous spurs on each hind leg. (note: tagline (final pass)) |
| once thought to be a taxidermist's hoax | it was thought to be a taxidermist's hoax (note: tagline (final pass)) |

## Genome analysis of the platypus reveals unique signatures of evolution.

https://doi.org/10.1038/nature06936

| The page says | The source says |
| :--- | :--- |
| The paper reporting its genome sums up the mix: platypus females lactate, yet lay eggs, and males are equipped with venom similar to that of reptiles | This monotreme exhibits a fascinating combination of reptilian and mammalian characters. For example, platypuses have a coat of fur adapted to an aquatic lifestyle; platypus females lactate, yet lay eggs; and males are equipped with venom similar to that of reptiles |
| When a platypus forages underwater, its eyes, ears and nostrils are closed, and an electrical sense in its bill helps it find prey | With its eyes, ears and nostrils closed while foraging underwater, it uses an electro-sensory system in the bill to help locate aquatic invertebrates and other prey |
| With their bills | it uses an electro-sensory system in the bill to help locate aquatic invertebrates and other prey |
| an electric sense in its bill | With its eyes, ears and nostrils closed while foraging underwater, it uses an electro-sensory system in the bill to help locate aquatic invertebrates and other prey (note: tagline (final pass)) |

## Manger & Pettigrew (2008). Ultrastructure, Number, Distribution and Innervation of Electroreceptors and Mechanoreceptors in the Bill Skin of the Platypus, Ornithorhynchus anatinus (Part 1 of 2). Brain, Behavior and Evolution.

https://doi.org/10.1159/000113185

| The page says | The source says |
| :--- | :--- |
| Electroreceptive bill with 40,000 electroreceptors, venomous hind-leg spurs, and cyan-green UV biofluorescence | There are 40,000 mucous gland electroreceptors found in the bill skin of the platypus (note: venomous hind-leg spurs covered by the defensins-2008 claim; biofluorescence covered by anich-2020 claim) |
| plus 46,500 touch receptors | A push-rod mechanoreceptor, similar in morphology to Eimer's organ of the mole, and bill-tip organs in birds, was also found in the bill skin ... Although less numerous than the mechanoreceptors (46,500 mechanoreceptors compared with 13,500 sensory serous glands) |
| In 2008, researchers who mapped the bill called the platypus "presently the only mammal demonstrated to use electroreception to obtain food." | The platypus is presently the only mammal demonstrated to use electroreception to obtain food. (note: 2008 is the paper's year; the sentence is dated because 'presently' is a 2008 state) |
| Underwater, a platypus keeps its eyes, ears and nostrils closed and locates prey with sensors in its bill: about 40,000 that detect electric fields and 46,500 that respond to touch | There are 40,000 mucous gland electroreceptors found in the bill skin of the platypus ... Although less numerous than the mechanoreceptors (46,500 mechanoreceptors compared with 13,500 sensory serous glands) (note: eyes/ears/nostrils closed from genome-2008: 'With its eyes, ears and nostrils closed while foraging underwater') |
| A 2008 study of the bill's anatomy called the platypus the only mammal then shown to find food by electroreception | The platypus is presently the only mammal demonstrated to use electroreception to obtain food. ... This paper presents an anatomical study of the basis of electroreception in the platypus. (note: 2008 is the reference year) |

## Ordoñez et al. (2008). Loss of genes implicated in gastric function during platypus evolution. Genome Biology.

https://doi.org/10.1186/gb-2008-9-5-r81

| The page says | The source says |
| :--- | :--- |
| A 2008 genetic study found that platypuses have lost the main genes for making and using gastric juice, including those for pepsin and the stomach's acid pump | the main genes implicated in the formation and activity of gastric juice have been lost in platypus. These include the aspartyl proteases pepsinogen A and pepsinogens B/C, the hydrochloric acid secretion stimulatory hormone gastrin, and the alpha subunit of the gastric H+/K+-ATPase. (note: acid pump = gastric H+/K+-ATPase; 2008 is the reference year) |
| Losing the genes for the stomach's acid pump explains at least part of that, according to a 2008 genome study | confirms the absence of a functional H + /K + -ATPase in this vertebrate and provides at least part of the explanation for the lack of acid secretion in the platypus stomach (note: 2008 is the reference year) |

## Nicol (2025). Does the platypus have a stomach? The perils of popular science. Australian Zoologist.

https://doi.org/10.7882/az.2025.011

| The page says | The source says |
| :--- | :--- |
| That's not the same as having no stomach, a claim a 2025 review uses as an example of how "science misinformation can be propagated." | show how the absence of acid secretion has been confused with absence of a stomach. The misunderstanding and misrepresentation of platypus anatomy and physiology provides an interesting example of how science misinformation can be propagated. (note: 2025 is the reference year) |
| Platypuses "do have stomachs," the review says, just non-secretory ones, unlike those of all other mammals | platypuses and echidnas do have stomachs, although they differ from the stomachs of all other mammals by being non-secretory |
| A 2025 review of the widespread claim that the platypus has no stomach found it wrong: platypuses do have a stomach, but it doesn't secrete digestive juices | If you search the internet for platypus stomach you will find countless websites stating that the platypus has no stomach ... But platypuses and echidnas do have stomachs, although they differ from the stomachs of all other mammals by being non-secretory. (note: 2025 is the reference year) |

## Anich et al. (2020). Biofluorescence in the platypus (Ornithorhynchus anatinus). Mammalia.

https://doi.org/10.1515/mammalia-2020-0027

| The page says | The source says |
| :--- | :--- |
| Under ultraviolet light, the brown fur of three museum specimens glowed green or cyan, the first biofluorescence reported in any monotreme | We examined three specimens of the platypus ( Ornithorhynchus anatinus ) from Tasmania and New South Wales, Australia, housed in the Field Museum of Natural History (Chicago, Illinois, USA) and the University of Nebraska State Museum (Lincoln, Nebraska, USA) under visible light and ultraviolet (UV) light. The pelage of the animals appeared uniformly brown under visible light and green or cyan under UV light, due to fluoresced wavelengths that peaked around 500 nm. Our observations are the first report of biofluorescence in a monotreme mammal. |
| Their fur biofluoresces | The pelage of the animals appeared uniformly brown under visible light and green or cyan under UV light |
| In a 2020 study, researchers shone UV light on three museum specimens | We examined three specimens of the platypus ( Ornithorhynchus anatinus ) from Tasmania and New South Wales, Australia, housed in the Field Museum of Natural History (Chicago, Illinois, USA) and the University of Nebraska State Museum (Lincoln, Nebraska, USA) under visible light and ultraviolet (UV) light. (note: 2020 is the reference year) |
| Fur that looked plain brown in normal light showed green or cyan, from emitted light peaking around 500 nanometres | The pelage of the animals appeared uniformly brown under visible light and green or cyan under UV light, due to fluoresced wavelengths that peaked around 500 nm. |
| It was the first report of biofluorescence in any monotreme | Our observations are the first report of biofluorescence in a monotreme mammal. |

## Woinarski & Burbidge (2016). Ornithorhynchus anatinus. The IUCN Red List of Threatened Species 2016: e.T40488A21964009.

https://doi.org/10.2305/iucn.uk.2016-1.rlts.t40488a21964009.en

| The page says | The source says |
| :--- | :--- |
| Near Threatened | IUCN Red List category: Near Threatened (NT). (note: assessment category read through GBIF's copy of the Red List per docs/fact-check.md) |