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New-ish Light Shed on Basic Phorusrhacid Call Structure
Topic Started: Aug 4 2017, 09:30 PM (418 Views)
Dr Nitwhite
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Not sure if any of you have seen this (it is two years old after all, so perhaps it was already posted [nothing showed up in my searches]), but I found it pretty interesting. Essentially, by looking at the structure of a very well preserved inner ear (on a fairly new species of phorusrhacid, Lallawavis scagliai), it was determined that these birds had a very narrow range of hearing at low sound frequencies, but which they should have been able to detect well. This lends evidence that their calls, if they used many vocalizations, would have been very deep, and possibly that their prey species would have had similarly deep calls.

http://www.eartharchives.org/articles/terror-birds-had-booming-calls/

2015 paper- http://www.tandfonline.com/doi/abs/10.1080/02724634.2014.912656 (unfortunately abstract only, the paper is behind a pay wall)
Edited by Dr Nitwhite, Aug 4 2017, 09:31 PM.
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LittleLazyLass
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Not sure what it is about this study in particular, but I swear I've consistently seen people just now learning about it for about two years straight now since I heard it when the paper it. Anyway, better more people know, I guess.
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I don't even really like this song that much but the title is pretty relatable sometimes, I guess.
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Beetleboy
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Wow, cool. Thanks for sharing this!
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kusanagi
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Someone compared the bill morphology to that of Gyps, Macronectes and Harpagornis. Not sure what prey they preferred but without a flying birds talons that prey was pretty small. Seriemas will smash small animals on the ground and other birds without large talons - such as skuas and large seagulls - will overpower comparatively large prey items by force. Even then the neck and skull of phorusrhacids are built to withstand vertical stresses not horizontal stress from large, powerful prey. This led to speculation the tip of the bill was used to strike but the skull was evolved to stand stress at mid length of the bill, not the tip. Conceivably feet were used as weapons also but most prey was small, else torn open alive, or they fed on carrion regularly.
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TAXESbutNano
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kusanagi
Aug 5 2017, 06:16 AM
Someone compared the bill morphology to that of Gyps, Macronectes and Harpagornis. Not sure what prey they preferred but without a flying birds talons that prey was pretty small. Seriemas will smash small animals on the ground and other birds without large talons - such as skuas and large seagulls - will overpower comparatively large prey items by force. Even then the neck and skull of phorusrhacids are built to withstand vertical stresses not horizontal stress from large, powerful prey. This led to speculation the tip of the bill was used to strike but the skull was evolved to stand stress at mid length of the bill, not the tip. Conceivably feet were used as weapons also but most prey was small, else torn open alive, or they fed on carrion regularly.
Unlikely- this is the exact same skull design used in theropods such as Allosaurus, which was designed to be used to cut through flesh while being driven by the powerful neck and leg musculature. It's likely that terror birds were the same, using whole-body strength to rip and tear flesh, while using their mobility to ensure stress remained on the vertical plane- they could just let go and readjust with another lunge if they couldn't. Duane Nash has a few good posts on the matter.
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kusanagi
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Aug 5 2017, 07:19 AM
kusanagi
Aug 5 2017, 06:16 AM
Someone compared the bill morphology to that of Gyps, Macronectes and Harpagornis. Not sure what prey they preferred but without a flying birds talons that prey was pretty small. Seriemas will smash small animals on the ground and other birds without large talons - such as skuas and large seagulls - will overpower comparatively large prey items by force. Even then the neck and skull of phorusrhacids are built to withstand vertical stresses not horizontal stress from large, powerful prey. This led to speculation the tip of the bill was used to strike but the skull was evolved to stand stress at mid length of the bill, not the tip. Conceivably feet were used as weapons also but most prey was small, else torn open alive, or they fed on carrion regularly.
Unlikely- this is the exact same skull design used in theropods such as Allosaurus, which was designed to be used to cut through flesh while being driven by the powerful neck and leg musculature. It's likely that terror birds were the same, using whole-body strength to rip and tear flesh, while using their mobility to ensure stress remained on the vertical plane- they could just let go and readjust with another lunge if they couldn't. Duane Nash has a few good posts on the matter.
Yes I was thinking of Nash but there exist differences such as the lack of forearms and teeth. I never am sure how useful hooked bills are: flying raptors and owls use their feet primarily and raptors use their tongues to process meat. It would appear then that bills are inferior to claws or teeth at tearing or piercing flesh. Not saying the similarities to allosauroid dinosaurs aren't there, but the similarity is not perfect.
Edited by kusanagi, Aug 5 2017, 07:39 AM.
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Dr Nitwhite
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Aug 4 2017, 11:09 PM
Not sure what it is about this study in particular, but I swear I've consistently seen people just now learning about it for about two years straight now since I heard it when the paper it. Anyway, better more people know, I guess.
Where these people on discord? I heard about it on a server there and I imagine it might have just been making the rounds there.
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Final SE Lifelist standings

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We interrupt your regular programming to bring you this cutting edge report.
ATTENDANCE DROPS DRASTICALLY ON SE SERVER
This past Monday on Discord, famous server Speculative Evolution took a hit in the attendance office when it's offline member list suddenly reappeared. Mods scrambled to rectify the situation, but unfortunately there was little anyone could do. Server member Ivan was asked what he thought of the situation. "So long as Flisch, lord of machines and scion of Urborg lives, all will be well". SE, (in)famous for it's eccentric userbase, has recently been spiraling downward, and now we have hard conformation of the decline. Moderator "High Lord" Icthyander states "There is nothing to be concerned about, Discord is merely changing its UI again", but members are beginning to suspect the honesty of their staff.
Stay tuned, we'll be back with more at 11.
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LittleLazyLass
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I've heard people talking it now and then at various locations, but I don't remember seeing anything on our discord, just the Saurian one.
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I don't even really like this song that much but the title is pretty relatable sometimes, I guess.
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