Some young dinosaurs shed teeth, say experts
Some dinosaurs lost their teeth as they grew up, according to fossil evidence.
The hatchlings ate meat with their teeth, then used beaks to peck at plants as adults, say scientists.
The discovery is a surprise and has not been seen in any other reptile.
Limusaurus inextricabilis lived in China around 150 million years ago. The first fossilised remains of the animal were discovered about a decade ago.
"Initially, we believed that we found two different ceratosaurian dinosaurs from the Wucaiwan area, one toothed and the other toothless, and we even started to describe them separately," said Shuo Wang of Capital Normal University in Beijing, China, who led the research.
The palaeontologists then realised that the dinosaurs looked remarkably similar, except for the presence of teeth.
They found that the dinosaur lost its teeth over time, making it the first known reptile to do this.
Life cycle change
Dr Stephen Brusatte, of the University of Edinburgh, who was not part of the research team, said it was a stunning discovery.
"Up until now, who would have thought that there were dinosaurs that had teeth as babies, started to lose them as they grew up and then ended up as toothless adults with beaks?" he told BBC News.
"Nothing like this is seen in any other fossil vertebrate and the platypus is the only modern land-living vertebrate that does anything similar."
The dinosaurs were switching from one sort of feeding type that required teeth to one in which teeth were a disadvantage, and a beak was better, said Dr Stig Walsh of National Museums Scotland.
"Other theropod dinosaurs in the group to which Limusaurus belongs are carnivores and I can't help wondering whether the driver for such a life cycle change was to allow Limusaurus to capitalise on a more abundant food source as they became larger," he added.
Limusaurus (mud lizard) was a fairly old and primitive theropod dinosaur.
It belongs to the same group as well-known carnivores like T. rex and Velociraptor.
The researchers think the toothed juveniles were probably omnivorous meat-eaters. The adults, which had beaks, moved on to a plant-based diet.
The discovery will help explain how the beak, which is so important in the bird kingdom, evolved.
Tooth loss is more common in modern animals.
Some fish and amphibians lose teeth as they grow, as do platypuses.
The research is published in the journal Current Biology.
- NUJ 109th Birth anniversary 3369
- Mangala to urge 24-month extension 3540
- Namal slaps CBK with defamation 3444
- Pakistan still eyeing JF-17 Thunder Fighter sale to Sri Lanka 3151
- CID grills govt Printer, Director, others 3232
- LRC seeks Police protection 3141
- MR to meet Tamil and Muslim leaders 3212
- Leprosy hits western province 3150
- skipper of ill-fated boat remanded 3136
- Raggers will be promptly expelled 3164
- Double-speak from SB on Wimal 3167
- VX nerve agent killed Kim Jong-nam 3141
- More snags foul up Constitution making 3291
- NFPWHR warns of massive protest 3143
- Mangala meets US HDP delegation 3146
- SL Police deny ‘hunting’ refugees in HK 3135
- 1500 students denied Uni education 3219
- SLFP CMs to boycott meeting 3134
- Wimal not a party leader – Dayasiri 3141
- New Zealand-bound boat people held 3128
- February – a celebratory month 3116
- Political mayhem 3134
- Significance of Sri Lanka’s legal profession 3121
- Now or never for Havies 2249
- Bad light saves day for Isipathana 2245
- Golfer Arumugam no more 2246
- Royal resist late Joes’ onslaught 2251
- Sadeera's 177 n.o. guides SL 'A' 2242
- Sadeera pushes for Test spot 2521
- Wesley players face disciplinary action 2248
- De Villiers' record sets up thumping win 2235
- Australians humble India 2235
- Dilini edges Sadeepa in long jump 2239
- Ronaldinho launches soccer academy in China 2216
- French possess fear factor, says Zebo 2220
- UB Finance main sponsor for STC Rugby for 2017 2216
- New circular issued to allow player poaching 2322
- Malinda claims seven scalps 2218
- SAITM students will not be accepted by any country– Prof. Hiran Amerasekera 3164
- I have no issues with the Minister– Anoma Gamage 3510
- LG elections should be under new system 3335
- Google's self-driving firm sues Uber 2507
- Colombo Fashion Week dates for Summer season, 13 – 18 March 2513
- International Thunder Cat Power Boat Racing in Bentota- a thrilling experience 2508
- BPPL Holdings Limited announces Rs. 368 Mn IPO 2509
- Durdans Lab Service adds ‘Predictive Tests’ for disease prevention 2510
- INSEE Cement wins Green Platinum Award at HarithaSihinaya 2017 2509
- CIC to elevate education in rural Agri-Communities 2510
- NTB rewards 50 lucky American Express Cardmembers with latest iPhone 7 2509
- HNB offers new benefit package through agreement with Indra Traders 2520
- Crescent Global sponsors Insurance Awards 2508
- Hameedia’s Bespoke Tailoring offer 2501
- NDB relocates Wennappuwa branch 2501
- Foreign exits top Rs 120.6B 2502
- Brandix gifts stationery and school bags to 5,700 children 2499
- AIC Campus European State University Foundation after O/Levels 2501
- Valencia stun Real Madrid 2731
- GSP+ To sustain economy or to Mutate society? 3048
- Fully fledged Media Commission by June – DGI 3079
- A musical evening-Hindi film songs 3035
- Sitar recital 3031
- Alston Koch to sing at the ‘OSCARS’ after party 3037
- Luang Prabang – A Journey into Sublimity 3033
- Blue all the way 3033
- Footpaths Towards Deconstruction - Part 10 3035
- Employees rewarded 1327
- Training in excellence 1326
- Human – elephant conflict rears up again 1369
- Nature in its wild pristine beauty 1332
- A touch of Yalpanam 1332
- Blood facts 1328