# Are birds reptiles? Why the answer is confusing ![[images/Are-Birds-Reptiles.webp]] **Creator:** Joel is Curious · **Published:** 2026-10-13 · **Length:** 1:02 (YouTube Short) · [Watch on YouTube](https://www.youtube.com/watch?v=fiwnB7GYOHk) > Caption source: **YouTube auto-generated English captions (en-orig)**, fetched with yt-dlp (android_vr client) on the second try, after one HTTP 429. No TubeAlfred credits were used. Timestamps are from the captions; the captions stop mid-word at 0:58 ("Science"). The short is a vertical talking-head take filmed in a car, with burned-in captions, two comment cards ("Dinosaurs are not dinosaur any more" and "Birds are dinosaurs" style replies), and nested-box diagrams (reptiles ⊃ dinosaurs ⊃ birds; then crocodiles & alligators and dinosaurs/birds grouped apart from turtles and lizards & snakes). Screenshots are one about every 20 s. ## Summary "Which group of living animals are birds closest to? The answer is crocodiles and alligators." When the creator went to school, the groups were reptiles and birds. "In 1950, they changed the classification so that if your ancestors are in a group, you are in that group as well." In his last video he deliberately described birds as coming from dinosaurs "but also still being dinosaurs." Dinosaurs are in the reptile group, "which means birds are also reptiles." Over 240 million years ago one reptile group split off and became the dinosaurs and the crocodiles and alligators. Since birds came from dinosaurs, which came from that group, birds are closer to crocodiles and alligators than to turtles and other reptiles. Commenters who said birds are not reptiles "are right because there've been two different classifications, and a lot of people learned that in school. But the classifications have changed." The description spells out the two definitions: the traditional class (lizards, snakes, turtles, crocodiles, tuatara; birds separate) and the clade (everything descended from the common ancestor of lizards and crocodiles, which includes birds). It adds that this doesn't make mammals reptiles, since the mammal and reptile lines had already split about 310–330 million years ago, and corrects the short's "1950": Willi Hennig proposed the method in 1950, and it caught on after the 1966 English translation. ## Outline ### 0:00 Closest relatives, and a changed classification - [0:00](https://www.youtube.com/watch?v=fiwnB7GYOHk&t=0s) "Which group of living animals are birds closest to? The answer is crocodiles and alligators." - [0:06](https://www.youtube.com/watch?v=fiwnB7GYOHk&t=6s) "When I went to school, the groups were reptiles and birds. In 1950, they changed the classification so that if your ancestors are in a group, you are in that group as well." ![[images/Are-Birds-Reptiles-t0003.webp]] ### 0:13 Birds are dinosaurs, so birds are reptiles - [0:13](https://www.youtube.com/watch?v=fiwnB7GYOHk&t=13s) "In my last video, I was intentional when I described birds as coming from dinosaurs, but also still being dinosaurs." - [0:23](https://www.youtube.com/watch?v=fiwnB7GYOHk&t=23s) "Dinosaurs are in the reptile group, which means birds are also reptiles." - [0:28](https://www.youtube.com/watch?v=fiwnB7GYOHk&t=28s) "Over 240 million years ago, one reptile group split off, and that group became the dinosaurs and the crocodiles and alligators." ![[images/Are-Birds-Reptiles-t0023.webp]] ### 0:38 Closer to crocodiles than to turtles; both answers are right - [0:38](https://www.youtube.com/watch?v=fiwnB7GYOHk&t=38s) "Birds are closer to crocodiles and alligators than they are to turtles and other reptiles." - [0:49](https://www.youtube.com/watch?v=fiwnB7GYOHk&t=49s) "People in the comments who were saying that birds are not reptiles are right because there've been two different classifications... But, the classifications have changed. Look it up if you want." ![[images/Are-Birds-Reptiles-t0043.webp]] ## Anti-evolution argument *Stated fairly, from a leading creationist ministry. The short itself doesn't argue against creationists; it answers commenters.* - **Birds and reptiles were created separately:** Answers in Genesis (David Menton) says "Birds were created on Day Five and dinosaurs on Day Six," so birds can't descend from dinosaurs. It stresses "the fact that dinosaurs are reptiles," while birds are distinct: warm-blooded where living reptiles are cold-blooded, with a unique "flow-through" lung [R5]. - **Feathered "dinosaurs" are birds:** AiG argues that the feathered fossils used to link the two are "extinct kinds of birds," not dinosaurs [R6]. - **So "birds are reptiles" is a definition, not a discovery:** grouping by ancestry presupposes evolution; by the traditional definition (shared features), birds are not reptiles, and many classifications still treat them as separate. ## Answer *Point by point. Numbers refer to the References table.* ### 1. Both answers are right, as the creator says - Grouping by shared features gives the traditional classes; grouping by descent (clades) puts birds inside reptiles. Both are still in use. The U.S. government's Integrated Taxonomic Information System still lists Aves as a class separate from Reptilia (checked 2026-11-01) [R4], so "the classifications have changed" is only partly true: many references still use the older ranks. - The creationist point that a clade definition presupposes a family tree is fair: the short doesn't present evidence for the tree itself. That evidence is elsewhere (anatomy, fossils, genomes) [R1, R2]. ### 2. Birds' closest living relatives are crocodilians - Genome-scale studies place turtles as the sister group of archosaurs (birds and crocodiles) [R3], and crocodilian genomes are analyzed in that frame, "the group that includes crocodilians, dinosaurs, and birds" [R2]. So birds are closer to crocodiles than to turtles, lizards or snakes: accurate. ### 3. "Over 240 million years ago" - Archosaurs, the group of crocodilians and dinosaurs (including birds), have "a nearly 250 million year record that originated shortly after the Permian-Triassic extinction event" [R7]. "Over 240 million years" is accurate, if anything conservative. Strictly, the archosaurs also included pterosaurs and other extinct groups, which the short skips. ### 4. "In 1950 they changed the classification" - Loose, as the creator concedes in the description. Willi Hennig published his method in German in 1950; the English *Phylogenetic Systematics* (1966) [R8] was translated from a revised manuscript and is what spread it. No single body "changed the classification"; cladistics was adopted gradually from the 1960s on, and traditional ranks remain in use [R4]. ### 5. Answering the creationist case - The separate-creation view [R5, R6] is a theological claim; the short doesn't engage it. On the evidence, the traits AiG treats as uniquely avian appear step by step in dinosaurs: feathered non-bird paravians such as *Anchiornis* had "long feathers" on arms and legs [see [[The halfway animal (Response to Christian Destroys Evolutionist Teacher, Part 3)]]], and the bird body plan was "pieced together gradually over tens of millions of years" [R1]. AiG's reply is to classify the feathered forms as birds [R6], which is why the boundary keeps moving. ### 6. Doesn't this make mammals reptiles? - No, as the description says: the mammal and reptile lines split earlier. The description's quotation from Green et al. ("the divergence of mammals and reptiles at ~310 to 330 Ma") is reworded; the paper gives "~310–330 MYA" for that split [R2], so the substance is accurate. ## Key takeaways - Birds' closest living relatives are crocodiles and alligators. - By family tree, birds are dinosaurs and dinosaurs are reptiles, so birds are reptiles; by the traditional classes, they aren't. Both are in use. - The family-tree method came from Willi Hennig (1950; English 1966), not a 1950 rule change. - Creationists see the clade definition as presupposing evolution; the short asserts the tree rather than defending it. ## Things mentioned ### Organisms - Birds; dinosaurs; crocodiles and alligators; turtles; lizards, snakes and tuatara (description); mammals (description) ### People - Willi Hennig (description) ### Ideas - Traditional (Linnaean) classes vs. clades; archosaurs; the bird–crocodile split ### Works (from the description) - Brusatte, O'Connor & Jarvis 2015; Green et al. 2014; ITIS; Hennig 1950 and 1966 ### Links from the description - https://joeliscurious.com · https://www.instagram.com/joeliscurious/ · https://www.tiktok.com/@joeliscurious · https://x.com/JoelisCurious · https://www.youtube.com/@joeliscurious ## Claims check | Claim in the video | Verdict | Source or note | |---|---|---| | Birds' closest living relatives are crocodiles and alligators | **Accurate** | [R2, R3] | | In 1950 the classification changed so descendants belong to their ancestors' group | **Loose** | Hennig 1950; English 1966 [R8]; adopted gradually (creator's own correction) | | Birds are dinosaurs, and dinosaurs are reptiles, so birds are reptiles | **Accurate by the clade definition** | [R1] | | Over 240 million years ago one reptile group split off and became dinosaurs and crocodilians | **Accurate** | Archosaurs, "nearly 250 million year record" [R7] | | Birds are closer to crocodilians than to turtles and other reptiles | **Accurate** | [R3] | | Commenters saying birds aren't reptiles are right by the older classification | **Accurate** | ITIS still lists Aves as a separate class [R4] | | The classifications have changed | **Partly accurate** | Both systems are in use [R4] | | (Description) Mammals and reptiles diverged about 310–330 million years ago | **Accurate; quote reworded** | [R2] | ## References | # | Source | Exists? | Use in the video / role | Link | |---|---|---|---|---| | R1 | Brusatte, O'Connor & Jarvis, "The Origin and Diversification of Birds," *Current Biology* 25:R888–R898 (2015) | **Exists** (abstract read) | Description source: birds from theropod dinosaurs | [doi:10.1016/j.cub.2015.08.003](https://doi.org/10.1016/j.cub.2015.08.003) | | R2 | Green et al., "Three crocodilian genomes reveal ancestral patterns of evolution among archosaurs," *Science* 346:1254449 (2014) | **Exists** (abstract and full text read, PMC4386873) | Description source: archosaurs; mammal–reptile split about 310–330 Ma | [doi:10.1126/science.1254449](https://doi.org/10.1126/science.1254449) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC4386873/) | | R3 | Chiari et al., "Phylogenomic analyses support the position of turtles as the sister group of birds and crocodiles (Archosauria)," *BMC Biology* 10:65 (2012) | **Exists** (abstract read) | Added: turtles outside the bird–crocodile group | [doi:10.1186/1741-7007-10-65](https://doi.org/10.1186/1741-7007-10-65) | | R4 | Integrated Taxonomic Information System (ITIS) | **Exists** (queried 2026-11-01: Aves, TSN 174371, and Reptilia, TSN 173747, are separate classes) | Description source; shows the traditional ranks still in use | [itis.gov](https://www.itis.gov) | | R5 | Menton, "Did Dinosaurs Turn into Birds?," Answers in Genesis, 2008 (*The New Answers Book 1*) | **Exists** (read) | Added: creationist view; "Birds were created on Day Five and dinosaurs on Day Six"; quotes accurate | [answersingenesis.org](https://answersingenesis.org/dinosaurs/feathers/did-dinosaurs-turn-into-birds/) | | R6 | "Why Birds Are Not Dinosaurs," Answers in Genesis | **Exists** (read) | Added: feathered "dinosaurs" as "extinct kinds of birds" | [answersingenesis.org](https://answersingenesis.org/young-earth-evolution/why-birds-are-not-dinosaurs/) | | R7 | Nesbitt, "The Early Evolution of Archosaurs: Relationships and the Origin of Major Clades," *Bulletin of the AMNH* 352 (2011) | **Exists** (abstract read) | Added: archosaur origin about 250 Ma | [doi:10.1206/352.1](https://doi.org/10.1206/352.1) | | R8 | Hennig, *Phylogenetic Systematics* (University of Illinois Press, 1966; paperback 1999) | **Exists** (publisher page read) | Description source: the 1966 English edition | [UI Press](https://www.press.uillinois.edu/books/?id=p068140) | ### Not found or not checked - Hennig, *Grundzüge einer Theorie der phylogenetischen Systematik* (1950): a real book, named in the description, but no online copy was checked. - R6's author isn't shown in the page text that was read. ## Added context - **Series:** Not part of a numbered series. "My last video" refers to the dinosaur-to-bird responses: [[Birds from dinosaurs (Response to Christian Destroys Evolutionist Teacher, Part 1)]] and [[The halfway animal (Response to Christian Destroys Evolutionist Teacher, Part 3)]] (previous upload). Next upload: [[Why not carbon dating (The Age of the Earth, Part 2)]]. ## Biographies ### Joel is Curious (the creator) YouTube channel **Joel is Curious**, 21 uploads (all Shorts) from 2026-10-04. In his own words (video description): "I'm Joel, a software developer and former tech executive who likes to learn stuff. Science, history, Buddhism, Stoicism, and the thinkers behind them." He lists his sources in each description. (Sources: the video and its description.) ### Willi Hennig Author of the method behind clade-based classification, published in German in 1950 and in English as *Phylogenetic Systematics* (University of Illinois Press, 1966) [R8]. (Source: the video description and the publisher's page.)