I am pleased to provide a review of the contribution Raptorial appendages of the Cambrian apex predator Anomalocaris are built for soft prey and speed. This is a really elegant piece of work, which I really appreciated. It takes the raptorial appendages of the familiar well known Anomalocaris, simplifies them in a sensible manner, and then models them to identify types of preys by means of kinematic and CFD simulations.
The authors have my warmest congratulations on a lovely paper. I include few comments that are largely questions that came to me as I was reading the manuscript. My comments are in the order I read it, and so one of them was more or less answered as I read. The authors may like to consider which I hope the authors find the comments useful.

Introduction:
In general, is well written but maybe an additional paragraph explaining the importance of this work and how can lead to further research or improvements in the future would be beneficial.

Simulations:
Kinematic: This is well done following previous methodology by the authors. I have no problem at all. Only one small questions: Did the authors use collision detection to make sure that the podomeres did not interfere with each other, or hit the ventral surface of appendage?
FEA: My concern deals with the muscle used to run the analysis. You only use dorsal-ventral muscles, but maybe this represents an unrealistic simplification. From a biomechanical point of view, a part of longitudinal muscles could be necessary to flex the appendages. Dorsal longitudinal muscles must have functioned to extend the appendages whilst contraction of ventral longitudinal muscles enabled the appendages to flex. I am not sure whether a more complete scenario will provide the same results.
CFD simulations.
Why moving wall condition with the inlet velocity was no applied to the ground? Was Anomalocaris hunting in a static world?
Your model predicts an active hunting in the water column, what about close to the benthos? It will be nice to see the ground effect in your simulations. In fact this can have an important effect in the lift.
You only assess the drag, and you can see how low it is but what about the lift? If the lift is positive, then the appendages can move up making difficult to catch the preys while a negative lift may be more efficient to catch the preys.
On the other hand, I could not see the supplementary material, so maybe this is shown. How is the pressure coefficient in the ventral and dorsal sides of the frontal appendage. This also will provide information about my previous issue.
If I understand well, maybe not, you analysed only one of the pairs, why you do not simulate both frontal appendages and you assume there is no hydrodynamic influence one each other?

Minor
Line 1: According to the discussion, the authors identified that the shape of raptorial appendages in A. canadensis are optimized for soft prey capture and high speed, but it is not necessarily the case for other species of Anomalocarids. However, the authors did not discuss similar traits within the genera. To improve the manuscript, it is recommended to either change the title to specify that the results are only applicable to A. canadensis or to include a statement in the discussion section that supports the conclusion that similar traits are present in other species of Anomalocaris.
Line 70: The authors frequently reference FEA and CFD throughout the text, but only provide a full definition and acronym for FEA. This lack of consistency can be confusing for readers. It is recommended to provide the full names and acronyms for both methods here and in the corresponding methods subsections. After that, the methods should be referred to by their acronyms in the rest of the manuscript.
Line 87: how does the ‘Segmenting’ tool works for removing muscles and tendons as well as appendages? Does the software have its own criteria or are the authors using their own? In such case, which are them?
Line 88: Please cite Geomagic Studio
Line 136: This needs a citation, as you have cited the following sentence as well
Line 142: Please add a citation, or merge it with the previous one at the end of the entire sentence
Line 146: Although you have the figure 3 depicting the origin and insertion points, and later you mention the specifics, to say “biologically realistic origin and insertion points…” seems arbitrary. It’s important to express what was the base for the location of the points if it’s based on the analogous ovigers of male pycnogonids or if it is so different that the points had to be modelled in another way. On the other hand, was there consistent criteria that you used to fix the points in your model along the different podomeres? If so, please specify it.
Line 149: Specimen ROMIP 61675 was used to scale the models, however the authors don’t provide a reason why they chose this as the scale and not the others, was it random? By size? By completeness? Please clarify.
Line 151: Authors put “Materialise”, however it’s not clear if that’s a tool of the software or a step.
Line 155: Please correctly cite Strand7
Line 156: This sentence could be incorporated into the previous one to avoid repetition: “These podomeres were then solid-meshed as independent homogenous structures in tet-4 elements in 3-matic and exported as a Nastran file for import into Strand7 FEA software [CITATION], where the podomere material properties were assigned.”
Lines 170-172: This sentence belongs to the Results or Discussion section.
Line 178: Please correctly cite Blender
Line 190: Please correctly cite COMSOL
Line 196: Which properties of water were assigned? Are those the same as the ones described in Line 207? If so, please combine both sentences in one. On the other hand, there is a small difference between the properties of saltwater and just water. Maybe negligible, but nevertheless I propose to include a short statement clarifying which kind did you used.
Lines 281-186: I believe that this piece of information belongs to the Methodology section

Best wishes,
Jorge Esteve